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Publication Number: FHWA-RD-06-138
Date: October 2006

Effects of Inlet Geometry on Hydraulic Performance of Box Culverts

Alternative Text

Figure 1. Photo. Culvert headbox under construction.

The figure is a photo of the culvert headbox used in the study under construction. From a raised and off-to-the-side position, the photo shows a man working on a grid of pipes.

Figure 2. Diagram. Arrangement of ceramic class pressure sensors.

The figure is a perspective, or three-dimensional, diagram. On the right side is a rectangular headbox, a term that is spelled head box open parenthesisas two words close parenthesis in the diagram. An arrow indicating the direction of flow is superimposed on its top. The arrow points to the left. Immediately to the left of the headbox is a rectangular culvert. Three small cylinders are on the bottom of the headbox, and another three are on the bottom of the culvert. The cylinders are labeled pressure sensors. A chart is superimposed over the pressure sensors. The chart has two plots, one labeled E.G.L. for elevation grade line, and the other labeled H.G.L. for hydraulic grade line. For the pressure sensors in the head box, the two plots are together. For the pressure sensors in the culvert, the two plots descend and diverge with the H.G.L. plot being the lower plot.

Figure 3. Sketch. Precast flared end section tested by Graziano and by McEnroe.

The figure is a perspective, or three-dimensional, sketch of a culvert end section. The distant portion of the perspective sketch is to the right and is a cylindrical shape that is part of the culvert body. The near portion of the perspective sketch is to the left and is the actual flared end section. Beginning at the cylindrical culvert body, the sides and bottom of the end section, which has no top, spread out, or flare. The bottom is flat and joins the sides at right angles. The sides are short at the front but increase in height as they approach the culvert body. At the culvert body, the sides are the same height as the body.

Figure 4. Equation.H W slash D, prefabricated metal end section, unsubmerged condition.

For the quotient greater than or equal to 0 and less than or equal to 0.41 of Q divided by the square root of the product of g times D to the power of 5, the quotient of H W divided by D equals the product of 1.60 times the quotient to the 0.60 power of Q divided by the square root of the product of g times D to the power of 5.

Figure 5. Equation.H W slash D, prefabricated metal end section, transition zone.

For the quotient greater than or equal to 0.41 and less than or equal to 0.62 of Q divided by the square root of the product of g times D to the power of 5, the quotient of H W divided by D equals the sum of the product of 2.23 times the quotient of Q divided by the square root of the product of g times D to the power of 5, all added to 0.023.

Figure 6. Equation.H W slash D, prefabricated metal end section, submerged condition.

For the quotient greater than or equal to 0.62 and less than or equal to 1.20 of Q divided by the square root of the product of g times D to the power of 5, the quotient of H W divided by D equals the sum of three terms. The first term is 1.289. The second term is the negative of the product of 1.61 times the quotient of Q divided by the square root of the product of g times D to the power of 5. The third term is the product of 2.90 times the quotient to the power of 2 of Q divided by the square root of the product of g times D to the power of 5.

Figure 7. Equation.H W slash D, precast concrete end section, unsubmerged condition.

For the quotient greater than or equal to 0 and less than or equal to 0.42 of Q divided by the square root of the product of g times D to the power of 5, the quotient of H W divided by D equals the product of 1.53 times the quotient to the 0.55 power of Q divided by the square root of the product of g times D to the power of 5.

Figure 8. Equation.H W slash D, precast concrete end section, transition zone.

For the quotient greater than or equal to 0.42 and less than or equal to 0.68 of Q divided by the square root of the product of g times D to the power of 5, the quotient of H W divided by D equals the sum of the product of 2.13 times the quotient of Q divided by the square root of the product of g times D to the power of 5, all added to 0.055.

Figure 9. Equation.H W slash D, precast concrete end section, submerged condition.

For the quotient greater than or equal to 0.68 and less than or equal to 1.30 of Q divided by the square root of the product of g times D to the power of 5, the quotient of H W divided by D equals the sum of three terms. The first term is 1.367. The second term is the negative of the product of 1.50 times the quotient of Q divided by the square root of the product of g times D to the power of 5. The third term is the product of 2.50 times the quotient to the power of 2 of Q divided by the square root of the product of g times D to the power of 5.

Figure 10. Equation.Figure 7in H D S-5 format.

For the quotient greater than or equal to 0 and less than or equal to 3.04 of Q divided by the product of A times D to the one-half power, the quotient of HW divided by D equals the product of K subscript u times 0.515 times the quotient to the 0.55 power of Q divided by the product of A times D to the one-half power.

Figure 11. Sketch. Relationship of entrance loss coefficient to Reynolds number.

The figure is a sketch of a hypothetical graph. The x-axis is H W divided by D, which is a dimensionless ratio, and ranges from 0 to 2.5. The y-axis is K subscript e and the range is unlabeled. Four sets of markings are plotted. Each set has a Reynolds number, abbreviated Re. From top to bottom, the sets of Reynolds numbers of 75,000, 100,000, 200,000, and 300,000, respectively.

Figure 12. Diagram.Typical inlet control flow condition.

The figure is a side view schematic of a culvert, which is shown as a rectangle. The culvert slopes downward to the right. Thus the high end is to the left. Atop the culvert is a trapezoidal shape that represents a roadbed or other object. The culvert extends for a short distance beyond each end of the bottom of the trapezoidal shape. Three dotted lines are within the culvert. The topmost is labeled E.G.L., for energy grade line. The middle is labeled the critical depth line. The bottom is labeled H.G.L., for hydraulic grade line. Both the E.G.L. and the H.G.L. extend beyond the ends of the culvert. A number of distances or locations are indicated. On the left side of the diagram, two vertical lines are labeled 1 and 2, respectively. The line labeled 1 is before the culvert entrance. The line labeled 2 goes through the culvert just to the right of the entrance. The accompanying report text discusses equations that measure an energy balance between 1 and 2. Also on the left side of the diagram, the vertical distance between the bottom of the culvert and the E.G.L. before it enters the culvert is labeled H W. Near the left end of the culvert, the vertical drop in the E.G.L. as it enters the culvert is labeled H subscript e. Also near the left end of the culvert, the vertical distance between the E.G.L. after it has entered the culvert and the bottom of the culvert is labeled H subscript c. Toward the right end of the culvert, the vertical distance between the bottom of the culvert and the H.G.L. is labeled y subscript n, and the vertical distance between the E.G.L. and the H.G.L. is labeled V subscript n, all squared, divided by the product of 2 times g. Several elevation markings with no dimensions are also on the diagram.

Figure 13. Equation. Unsubmerged form 1, inlet control.

The quotient of H W subscript i divided by D equals the sum of three terms. The first is the quotient of H subscript c divided by D. The second term is the product of K times the quotient to the M power of the product of K subscript u times Q divided by the product of A times D to the 0.5 power. The third term is the product of 0.7 times S.

Figure 14. Equation. Unsubmerged form 2, inlet control.

The quotient of H W subscript i divided by D equals the product of K times the quotient to the M power of the product of K subscript u times Q divided by the product of A times D to the 0.5 power.

Figure 15. Equation. Submerged form, inlet control.

The quotient of H W subscript i divided by D equals the sum of three terms. The first is the product of c times the quotient squared of the product of K subscript u times Q divided by the product of A times D to the 0.5 power. The second term is Y. The third term is the product of 0.7 times S.

Figure 16. Diagram. Outlet control for full flow condition.

The figure is a side view schematic of a culvert, which is shown as a rectangle. The culvert slopes downward to the right. Thus the high end is to the left. Atop the culvert is a trapezoidal shape that represents a roadbed or other object. The culvert extends for a short distance beyond each end of the bottom of the trapezoidal shape. Two dotted lines are above the culvert. The topmost is labeled E.G.L., for energy grade line. The bottom is labeled H.G.L., for hydraulic grade line. The lines are horizontal before and after the ends of the culvert; the portions above the culvert slope downward to the right. A number of distances or locations are indicated. To the left of the culvert's entrance on the left side of the diagram, a vertical line is labeled 1. To the right of the culvert's exit on the right side of the diagram, a vertical line is labeled 2. The accompanying text discusses equations that measure an energy balance between 1 and 2. The vertical distance between the E.G.L. and the H.G.L. before the culvert's entrance is labeled V subscript n, all squared, divided by the product of 2 times g. The vertical distance between the E.G.L. and the H.G.L. above the culvert is labeled V squared divided by the product of 2 times g. The vertical distance between the E.G.L. and the H.G.L. after the culvert's exit is labeled V subscript d, all squared, divided by the product of 2 times g. The vertical distance between the E.G.L. before it enters the culvert and the bottom of the culvert at the culvert's entrance is labeled H W. The vertical distance between the H.G.L. before it enters the culvert and the bottom of the culvert at the culvert's exit is labeled H W subscript o. The vertical drop in the E.G.L. as it enters the culvert is labeled H subscript e. The vertical drop the E.G.L. undergoes inside the culvert is labeled H subscript f. The vertical drop in the E.G.L. at the culvert's exit is labeled H subscript o. The vertical drop in the E.G.L. before the culvert's entrance and after the culvert's exit is labeled H subscript L. The vertical distance between the H.G.L. after the culvert's exit and the bottom of the culvert at the exit is labeled T W. Several elevation markings with no dimensions are also on the diagram.

Figure 17. Equation. Head-discharge relationship, outlet control.

The left side of the equation is the sum of two terms. The first term is H W subscript o. The second term is the quotient of V subscript u, all squared, divided by the product of 2 times g. The right side of the equation is the sum of three terms. The first is TW. The second is the quotient of V subscript lowercase d, all squared, divided by the product of 2 times g. The third is H subscript L.

Figure 18. Equation. Total energy losses

H subscript L equals the sum of H subscript L-e plus H subscript L-f plus H subscript L-o.

Figure 19. Equation. Entrance loss.

H subscript L-e equals the product of K subscript e times the quotient of V squared divided by the product of 2 times g.

Figure 20. Equation. Exit loss.

H subscript L-o equals the product of K subscript o times the difference between two quotients. The first quotient is V squared divided by the product of 2 times g. From this quotient is taken the second quotient, which is V subscript lowercase d, all squared, divided by the product of 2 times g.

Figure 21. Diagram. Data management flow chart.

The figure is a flow chart that shows the study's calculation procedure for obtaining inlet performance curves, inlet coefficients, and outlet coefficients. The starting point is on the left side of the chart and is a download of a computer screen showing a page of the LabVIEW software program. The title of the page is S D underscore Measure dot v i. Two paths leave S D underscore Measure dot v i. The top path goes to calibration. Two paths leave calibration, one to sensor reading, the other to manual reading. The paths rejoin after these functions, and the result enters the top of a second download of a computer screen, which is entitled S D underscore Data dot v i. The bottom path leaving S D underscore Measure dot v i goes to data acquisition. Two paths leave data acquisition, one to a second sensor reading function, the other to a second manual reading function. The paths rejoin after these functions and the result enters the bottom of S D underscore Data dot v i. One path leaves S D underscore Data dot v i and goes to realtest m m d d y y dot x l s. Two paths leave this function, the top one going to a third download of a computer screen, which is entitled S D underscore Inlet dot v i. Two results leave S D underscore Inlet dot v i. One is labeled performance space curves dot x l s. The other is the coefficients K, M, c, and Y. The bottom path leaving realtest m m d d y y dot x l s goes to a fourth download of a computer screen, which is entitled S D underscore Outlet dot v i. One result leaves S D underscore Outlet dot v i. That result is the coefficients K subscript e and K subscript o.

Figure 22. Equation. Regression analysis, chi-squared.

Chi squared equals the summation from i equal 0 to i equal N minus 1 of a quotient squared. The numerator of the quotient is the term y subscript i minus a nonlinear function consisting of x subscript i and a subscript 1 to a subscript M. The denominator of the quotient is sigma subscript i.

Figure 23. Equation. Fifth-order polynomial for H W slash D.

The quotient H W subscript i divided by D equals the sum of six terms. The first term is lowercase a. The second term is the product of b times the quotient of Q divided by the product of A times D to the power of 0.5. The third term is the product of c times the quotient to the power of 2 of Q divided by the product of A times D to the power of 0.5. The fourth term is the product of lowercase d times the quotient to the power of 3 of Q divided by the product of A times D to the power of 0.5. The fifth term is the product of e times the quotient to the power of 4 of Q divided by the product of A times D to the power of 0.5. The sixth term is the product of f times the quotient to the power of 5 of Q divided by the product of A times D to the power of 0.5.

Figure 24. Equation. Entrance loss coefficient.

The figure consists of two versions of the relationship between the same variables. The first version is a repetition of figure 20: H subscript L-e equals the product of K subscript e times the quotient of V squared divided by the product of 2 times g. The second version is K subscript e equals the quotient of H subscript L-e divided by the quotient of V squared divided by the product of 2 times g.

Figure 25. Diagram. Technique to determine H subscript L-e.

The diagram is a side view of the culvert experimental setup. The purpose of the diagram is to show the technique used to measure H subscript L-e. The technique involves extrapolating the E G L open parenthesis energy grade lines close parenthesis in the headbox and the culvert barrels to a common plane and then taking the difference in the E G L on the common plane. In the diagram, the headbox is on the left, the barrels are in the middle, and the tailbox is on the right. Blue shading, or dark shading in a black-and-white printout of this document, indicates the water levels in the headbox, barrels, and tailbox. Small rectangles representing E G L and small circles representing H G L open parenthesis hydraulic grade lines close parenthesis are depicted as being projected onto a common plane. A number of dimensions are given. The bottom of the headbox is 23.62 inches above the bottom of the diagram, which represents the floor. The headbox itself is 48.82 inches tall. The bottom of the left end of the barrels is 26.18 inches above the floor. The bottom of the right end of the barrels is 25.59 inches above the floor. The barrels are 119.69 inches long and have a downward slope to the right of 0.7 percent. The bottom of the tailbox is 21.65 inches above the floor, and the tailbox itself is 38.98 inches tall. At the right end of the headbox, H subscript L-e is indicated as having a height of 1.46 inches. At the left end of the tailbox, H subscript L-o is indicated as having a height of 3.79 inches The conversion factor for inches is 1 inch equals 2.54 centimeters. At the bottom of the diagram, the value of the quotient of Q divided by the product of A times D to the 0.5 power is given as 6.04 feet to the 0.5 power, per second open parenthesis 3.33 meters to the 0.5 power, per second close parenthesis. K subscript e is 0.42, and K subscript o is 1.04; both numbers are dimensionless.

Figure 26. Graph. Typical behavior of K subscript e versus discharge intensity.

The y-axis is K subscript e, a dimensionless number, and ranges from 0 to 2.7. The x-axis is the discharge intensity, which is the quotient of Q divided by the product of A times D to the 0.5 power, which is feet to the 0.5 power, per second, and ranges from 0 to 6.0. The conversion factor is 1 foot to the 0.5 power, per second, equals 0.552 meters to the 0.5 power, per second. The graph is divided into two parts, which are indicated by different shadings. The lighter shading on the left is labeled the unsubmerged inlet. The darker shading on the right is labeled the submerged inlet. Five data points are plotted in each part. The first two data points are for discharge intensities of 1.0 foot to the 0.5 power, per second, or less and are labeled as eliminated. The remaining three data points in the unsubmerged inlet portion range between discharge intensities of approximately 1.5 to 2.6 feet to the 0.5 power, per second, and K subscript e values of approximately 0.1 and 0.8. The average K subscript e value for the unsubmerged inlet portion is 0.41. The five data points in the submerged inlet portion are very close to their average K subscript e value of 0.39; their discharge intensities range from approximately 4.0 to 6.1 feet to the 0.5 power, per second.

Figure 27. Diagram and Photo. Mini-flume and PIV setup.

This is a two-part figure. Figure 27a, on the left, is a perspective, or three-dimensional, diagram of the particle image velocimetry open parenthesis PIV close parenthesis setup. The central portion of the diagram is a rectangular box that is divided into two sections. The right section is labeled flume. An arrow indicating the direction of flow is in the flume and is labeled "flow with particles." The arrow points to the left. The second section of the box is on the left side. Within the second section is a smaller rectangular shape that is labeled "culvert." Above the right end of the culvert is a light source that is projecting a light sheet into the culvert. Within the portion of the light sheet that is in the culvert are small dots representing the particles in the flow through the flume and culvert. In front of the box, a charge coupled device open parenthesis ccd close parenthesis camera records the movement of the particles. Figure 27b, on the right, is a photo of a portion of the setup portrayed in the diagram. The ccd camera is mounted on a framework in the foreground. In the background is a portion of the rectangular box.

Figure 28. Photos. Bevel models and PIV camera at culvert entrance.

This is a two-part figure, both parts being photos. Figure 28a, on the left, shows seven Plexiglass models of bevels lying side by side. Figure 28b, on the right, shows the lens end of the charge coupled device open parenthesis ccd close parenthesis camera pointing at the culvert entrance inside the miniflume.

Figure 29. Diagram. Integration of velocity flow field in stream functions to study culvert flow contraction.

This diagram is a flow chart showing the conversion of initial particle image velocimetry open parenthesis PIV close parenthesis images of velocity flow into streamlines that can be interpreted visually. The conversion takes place through the mathematical process of integration. The diagram has three components. The first component, in the upper left corner, is a download of a computer screen. The screen has a number of horizontal lines of small connected arrows. In the upper left of the screen, the lines are faded. Below this first component is the second component, the integration equation. The equation is Psi equals the difference of the integral over the set Y of U, with the variable of integration being dY, minus the integral over the set X of V, with the variable of integration being dX. The third component, on the right side of the figure, is a download of the computer screen resulting from the processing of the data of the first component by the integration equation, which is the second component. The final computer screen, the third component, has a large number of horizontal lines. In the upper left corner of the screen, the lines develop a spiral that produces an eddy shape.

Figure 30. Diagrams. Tested bevel edge conditions and effective flow depth criterion.

Tested bevel edge conditions and effective flow depth criterion. This figure contains eight side view sketches labeled figure a through figure h. Seven of the sketches are side views of bevel edges, or shapes. One of the edges is a 0-degree bevel angle. Three of the edges are chamfer edges. And three of the edges are square edges. The eighth sketch is a side view of the location of the bevel edge in the experimental arrangement. Dimensions in the sketches are in inches. One inch equals 2.54 centimeters. Here follows a detailed description of each of the eight sketches. Figure 30a is a side view of the experimental arrangement. The flow goes from left to right, entering a culvert near the left side of the sketch. The size of the culvert's entrance is labeled A. The top edge of the culvert's entrance is where the bevel edges are located for testing and is labeled Bevel edge condition. Well above the culvert's entrance is the water line. Above the culvert itself is the horizontal theoretical extension of the water line. Between the extension of the water line and the top of the culvert are the E.G.L. open parenthesis energy grade line close parenthesis and, below it, the H.G.L. open parenthesis hydraulic grade line close parenthesis. The maximum distance between the E.G.L. and the H.G.L. is labeled the quotient of V subscript 0, all squared, divided by the product of 2 times g. In the culvert below this maximum distance between the E.G.L. and the H.G.L., the flow reaches its most contracted point, which is labeled V subscript 0, Effective flow depth at vena contracta. The flow on the right side of the sketch is labeled V subscript 1. Figure 30b is a side view of a bevel edge with a 0-degree bevel angle. The side view of the edge is simply a rectangle with a height of 8 inches and a width of 10 inches. Figure 30c is a side view of an existing 4-inch chamfer. The chamfer is located at the lower left corner and is 4 inches high by 4 inches wide. The total width of the edge is a minimum of 8 inches and a possible maximum, indicated by dotted lines, of 10 inches. The horizontal, or straight, portion of the bottom side of the edge is 4 inches for the minimum 8-inch width. Figure 30d is a side view of a rounded bevel edge with a proposed 4-inch radius. The rounded edge is located at the lower left corner. The total width of the edge is a minimum of 8 inches and a possible maximum, indicated by dotted lines, of 10 inches. The horizontal, or straight, portion of the bottom side of the edge is 4 inches for the minimum 8-inch width. Figure 30e is a side view of a beveled edge with a proposed 6-inch chamfer. The chamfer is located at the lower left corner and is 6 inches high by 6 inches wide. The total width of the edge is a minimum of 8 inches and a possible maximum, indicated by dotted lines, of 10 inches. The horizontal, or straight, portion of the bottom side of the edge is 2 inches for the minimum 8-inch width. Figure 30f is a side view of a rounded bevel edge with a proposed 6-inch radius. The rounded edge is located at the lower left corner. The total width of the edge is a minimum of 8 inches and a possible maximum, indicated by dotted lines, of 10 inches. The horizontal, or straight, portion of the bottom side of the edge is 2 inches for the minimum 8-inch width. Figure 30g is a side view of a beveled edge with a proposed 8-inch chamfer. The chamfer is located at the lower left corner and is 8 inches high by 8 inches wide. The total width of the edge is 10 inches. The horizontal, or straight, portion of the bottom side of the edge is 2 inches. Figure 30h is a side view of a rounded bevel edge with a proposed 8-inch radius. The rounded edge is located at the lower left corner. The total width of the edge is 10 inches. The horizontal, or straight, portion of the bottom side of the edge is 2 inches.

Figure 31. Diagram. Culvert setup-side view.

This figure is a slightly different version of the side view in figure 25. The headbox, unlabeled, is to the left, the culvert barrel or barrels, unlabeled, are in the center, and the tailbox, also unlabeled, is to the right. Dimensions are in feet. The headbox is 4.0 feet high and 8.0 feet long. The distance between its bottom and the floor is 2.0 feet. The barrel or barrels are 10.2 feet long, and the distance between their left end and the floor is just over 2.0 feet. The barrel or barrels have a slope of 0.07 percent, with the high end being to the left. The tailbox is 3.0 feet high and 8.0 feet long. The distance between its bottom and the floor is 1.8 feet. On top of the left end of the tailbox is a drawing of a two-dimensional robot. The conversion factor for feet is 1 foot equals 0.305 meters.

Figure 32. Diagram. Culvert setup-top view.

In this top view, the headbox, labeled, is to the left, the barrel, unlabeled, is in the center, and the tailbox, labeled, is to the right. Dimensions are in feet. The headbox is 8.0 by 8.0 feet. The barrel is 10.0 by 2.0 feet. The tailbox is 8.0 by 6.0 ft. The top of a ladder is sketched on the left end of the headbox. A gate is indicated on the right end of the tailbox. A two-dimensional robot is indicated on top of the left end of the tailbox. Above the barrel is the legend FC-S-0 open parenthesis 4:1 close parenthesis, FC-S-0 being the model identification and 4:1 being the span to rise ratio. The conversion factor for feet is 1 foot equals 0.305 meters.

Figure 33. Photo. Culvert setup-overview.

In this overview, the tailbox is in the left foreground, and the headbox is to the right rear. The barrel or barrels in the middle are not discernable. The two-dimensional robot is on top of the far end of the tailbox.

Figure 34. Photo. Culvert model barrels.

The barrels are in the center of this photo. The headbox, only a small portion of which is visible, joins the barrels on the left side of the figure. On the right side, the barrels join the tailbox, a large portion of which is visible. The two-dimensional robot is on top of the tailbox.

Figure 35. Photo. Two-dimensional robot to measure velocity distribution in tailbox.

The two-dimensional robot rests on top of the front end of the tailbox. The barrels join the bottom of the front end of the tailbox. The barrels extend into the left foreground.

Figure 36. Photo. Groove connectors to assemble models.

This photo shows a framework of grooves into which wall pieces can be placed to model different types of culvert entrances. On each end of the framework is an angled groove that is labeled groove connection for FC open parenthesis field cast close parenthesis side wall 30-degree flare angle. Two nonangled center grooves are labeled groove connection for FC extended center wall.

Figure 37. Diagrams. Effective flow depth at vena contracta for nonrounded bevel edges.

Effective flow depth at vena contracta for nonrounded bevel edges. The figure contains four downloaded computer screens labeled 37a through 37d. Each screen is an image of streamlines from the processing of particle imaging velocimetry open parenthesis PIV close parenthesis results for flow, from left to right, into a culvert entrance with a particular bevel on the top edge. The dimensions in the four screens are in inches and millimeters. The conversion factor for inches is 1 inch equals 2.54 centimeters. Here follows a detailed description of each screen. Figure 37a, at the upper left, shows the effective flow depth for a bevel edge with a 0-degree bevel angle. The side view of the edge is in the upper left corner of the screen and is a rectangle with a height of 8 inches and a width of 10 inches. The streamlines are in the lower two-thirds of the screen. A substantial eddy is in the upper left corner of the streamlines, a distance of 42.132 millimeters from a location close to the bottom of the stream lines. Figure 37b, at the upper right, shows the effective flow depth for a bevel edge with an existing 4-inch chamfer. The chamfer is located at the lower left corner of the edge and is 4 inches high by 4 inches wide. The streamlines are in the lower two-thirds of the screen. A modest eddy is in the upper left corner of the streamlines, a distance of 44.23 millimeters from a location close to the bottom of the streamlines. Figure 37c, at the lower left, shows the effective flow depth for a bevel edge with a proposed 6-inch chamfer. The chamfer is located at the lower left corner of the edge and is 6 inches high by 6 inches wide. The streamlines are in the lower two-thirds of the screen. A small eddy is in the upper left corner of the streamlines, a distance of 47.58 millimeters from a location close to the bottom of the streamlines. Figure37d, at the lower right, shows the effective flow depth for a bevel edge with a proposed 8-inch chamfer. The chamfer is located at the lower left corner of the edge and is 8 inches high by 8 inches wide. The streamlines are in the lower two-thirds of the screen. A very small eddy is in the upper left corner of the streamlines, a distance of 47.216 millimeters from a location close to the bottom of the streamlines.

Figure 38. Diagrams. Effective flow depth at vena contracta for rounded bevel edges.

Effective flow depth at vena contracta for rounded bevel edges. The figure contains three downloaded computer screens labeled 38a through 38c. Each screen is an image of streamlines from the processing of particle imaging velocimetry results for flow, from left to right, into a culvert entrance with a particular bevel on the top edge. The dimensions in the three screens are in inches and millimeters. The conversion factor for inches is 1 inch equals 2.54 centimeters. Here follows a detailed description of each screen. Figure 38a, at upper left, shows effective flow depth for a proposed rounded bevel edge with a 4-inch radius. The rounded edge is located at the lower left corner of the edge. The streamlines are in the lower two-thirds of the screen. A modest eddy is in the upper left corner of the streamlines, a distance of 45.204 millimeters from a location close to the bottom of the streamlines. Figure 38b, at upper right, shows effective flow depth for a proposed rounded bevel edge with a 6-inch radius. The rounded edge is located at the lower left corner of the edge. The streamlines are in the lower two-thirds of the screen. A modest eddy is in the upper left corner of the streamlines, a distance of 47.268 millimeters from a location close to the bottom of the streamlines. Figure 38c, at the bottom, shows effective flow depth for a proposed rounded bevel edge with an 8-inch radius. The rounded edge is located at the lower left corner of the edge. The streamlines are in the lower two-thirds of the screen. There is little indication of an eddy. The distance from the top of the streamlines to a location close to the bottom is 52.061 millimeters.

Figure 39. Graph. Effective flow depth versus headwater-tailwater difference.

For seven bevel edges, this graph plots the effective flow depth at vena contracta versus the difference between the headwater and tailwater measurements. The x-axis is the difference between the headwater and tailwater in millimeters and ranges from 22.5 to 26.5. The y-axis is the effective flow depth at vena contracta in millimeters and ranges from 45 to 60. The side view of the experimental arrangement is inserted in the upper right corner of the graph. The flow goes from left to right, entering a culvert near the left side of the sketch. The size of the culvert's entrance is labeled A. Well above the culvert's entrance is the water line. Above the culvert itself is the horizontal theoretical extension of the water line. Between the extension of the water line and the top of the culvert are the E.G.L. open parenthesis energy grade line close parenthesis and, below it, the H.G.L. open parenthesis hydraulic grade line close parenthesis. The maximum distance between the E.G.L. and the H.G.L. is labeled the quotient of V subscript 0, all squared, divided by the product of 2 times g. In the culvert below this maximum distance between the E.G.L. and the H.G.L., the flow reaches its most contracted point, which is labeled V subscript 0, Effective flow depth at vena contracta. The flow on the right side of the sketch is labeled V subscript 1. The approximate effective flow depth at vena contracta and the approximate difference between the headwater and tailwater measurements for each of the seven bevel edges are open parenthesis in millimeters close parenthesis: 8-inch radius-57.8 and 23 millimeters; 6-inch radius-52.9 and 24 millimeters; 6-inch chamfer-53.2 and 25 millimeters; 8-inch chamfer-52.8 and 25 millimeters; 4-inch chamfer-49.9 and 25 millimeters; 4-inch radius-50.9 and 26 millimeters; and zero bevel angle-47.8 and 26 millimeters.

Figure 40. Sketches. Models tested for effects of bevels and corner fillets.

This figure contains sketches and descriptions of the six culvert entrance models that were tested for the effects of bevels and corner fillets. The six models, labeled 40a through 40f, each show a perspective, or three-dimensional, drawing, with the near portion of the model on the left side and the distant portion on the right side. Dimensions are in inches. One inch equals 2.54 centimeters. Here follows a detailed description of each model. Figure 40a is a sketch of HDS-5 Inlet, Chart 8, Scale 3. The Chart 8, Scale 3, reference is to a chart in the Federal Highway Administration's Hydraulic Design of Highway Culverts, Hydraulic Design Series No. 5. This model has 0-degree-flared wingwalls, a square edge at the crown, no wingwalls bevel, and no corner fillets. Figure 40b is a sketch of model FC-S-0 with 0-degree-flared wingwalls, a 4-inch-straight top bevel, no wingwalls bevel, and no corner fillets. Figure 40c is a sketch of model PC-A with 0-degree-flared wingwalls, an 8-inch-radius top bevel, a 4-inch-radius wingwalls bevel, and no corner fillets. Figure 40d is a sketch of model FC-S-30 with 30-degree-flared wingwalls, a 4-inch-straight top bevel, no wingwalls bevel, and 6-inch corner fillets. Figure 40e is a second sketch of model FC-S-0, this time with 0-degree-flared wingwalls, a 4-inch-straight top bevel, no wingwalls bevel, and 6-inch and 12-inch corner fillets. Figure 40f is a second sketch of model PC-A, this time with 0-degree-flared wingwalls, an 8-inch-radius top bevel, a 4-inch-radius wingwalls bevel, and 6-inch and 12-inch corner fillets.

Figure 41. Graph. Inlet control performance curves, FC-S-0 versus PC-A, zero corner fillets.

The x-axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three models-FC-S-0, PC-A, and HDS-5 8 slash 3-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. All of the models have single barrels and no corner fillets. For the unsubmerged condition, the plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. For the submerged condition, the three plots, which are in the upper right portion of the graph, begin at approximately the same x-axis and y-axis coordinates, 4 and 1.25, respectively. In rising to the right, the three plots diverge, but not by much. The plot for the HDS-5 8 slash 3 model-with 0-degree-flared wingwalls and a square edge top plate-rises most steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.25, respectively. The plot for the FC-S-0 model-with 0-degree-flared wingwalls and a 45-degree chamfer top plate-is the middle riser, ending at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively. The plot for the PC-A model-with 0-degree-flared wingwalls and an 8-inch top bevel-rises the least, ending at x-axis and y-axis coordinates of approximately 6 and 2, respectively. One inch equals 2.54 centimeters.

Figure 42. Graph. Inlet control performance curves, FC-S-0 versus PC-A, 6-inch fillets.

The x-axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-FC-S-0 and PC-A-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. For the submerged condition, the two plots, which are in the upper right portion of the graph, begin at approximately the same x-axis and y-axis coordinates, 4 and 1.25, respectively. In rising to the right, the two plots diverge, but not by much. The plot for the FC-S-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-rises most steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively. The plot for the PC-A model-with an 8-inch-radius top bevel and 6-inch corner fillets-rises the least, ending at x-axis and y-axis coordinates of approximately 6 and 2, respectively. One inch equals 2.54 centimeters.

Figure 43. Graph. Inlet control, precast with 6-inch fillets and field cast with 6-inch fillets.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three models-FC-S-30, FC-S-0, and PC-A-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots of FC-S-0 and PC-A, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The unsubmerged condition plot of FC-S-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.8, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-S-0 and PC-A begin at approximately the same x-axis and y-axis coordinates, 4 and 1.25, respectively. In rising to the right, the two plots diverge, but not by much. The plot for the FC-S-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-rises most steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively. The plot for the PC-A model-with an 8-inch-radius top bevel and 6-inch corner fillets-rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6 and 2, respectively. The submerged condition plot for the FC-S-30 model-with 30-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-is a bit lower than the plots for the FC-S-0 and PC-A models. The x-axis and y-axis coordinates of the leftmost point are approximately 4 and 1.2, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 6 and 1.9, respectively. One inch equals 2.54 centimeters.

Figure 44. Graph. Inlet control, field cast hybrid inlet with 4-inch-radius bevel on wingwalls.

The x-axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-FC-S-0 and FC-hybrid-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Both models have a single barrel, a field cast top bevel, and 0-inch corner fillets. For the unsubmerged condition, the plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1.1, respectively. For the submerged condition, the two plots, which are in the upper right portion of the graph, are again virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.3, respectively. The x-axis and y-axis coordinates of the rightmost points are approximately 6 and 2.25, respectively. The FC-S-0 model has a field cast top plate and field cast wingwalls. The FC-hybrid model has a field cast top plate and precast wingwalls. One inch equals 2.54 centimeters.

Figure 45. Graph. Inlet control, precast hybrid inlet with no bevel on wingwalls.

The x-axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-PC-A and PC-hybrid-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Both models have a single barrel, an 8-inch-radius top bevel, and 0-inch corner fillets. For the unsubmerged condition, the plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1.1, respectively. For the submerged condition, the two plots, which are in the upper right portion of the graph, begin at approximately the same x-axis and y-axis coordinates, 4 and 1.3, respectively. In rising to the right, the two plots diverge, but not by much. The plot for the PC-A model-with a precast top plate and precast wingwalls-rises most steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.1, respectively. The plot for the PC-hybrid model-with a precast top plate and field cast wingwalls-rises the least, ending at x-axis and y-axis coordinates of approximately 6 and 2, respectively. One inch equals 2.54 centimeters.

Figure 46. Graph. Inlet control effects of corner fillets for the field cast model.

The x-axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio H W divided by D and ranges from 0 to 2.5. Three models-FC-S-0 with 0-inch corner fillets, FC-S-0 with 6-inch corner fillets, and FC-S-0 with 12-inch corner fillets-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. All models have a single barrel and 0-degree wingwall flare. For the unsubmerged condition, the plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1.0, respectively. For the submerged condition, the plots, which are in the upper right portion of the graph, are again virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.3, respectively. The x-axis and y-axis coordinates of the rightmost points are approximately 6 and 2.2, respectively. One inch equals 2.54 centimeters.

Figure 47. Graph. Inlet control effects of corner fillets for the precast model.

The x-axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio H W divided by D and ranges from 0 to 2.5. Three models-PC-A with 0-inch corner fillets, PC-A with 6-inch corner fillets, and PC A with 12-inch corner fillets-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. All models have an 8-inch-radius top bevel and a single barrel. For the unsubmerged condition, the plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1.0, respectively. For the submerged condition, the plots, which are in the upper right portion of the graph, are again virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.25, respectively. The x-axis and y-axis coordinates of the rightmost points are approximately 6 and 2.0, respectively. One inch equals 2.54 centimeters.

Figure 48. Graph. Inlet control, precast with 12-inch fillets and field cast with 6-inch fillets.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three models-FC-S-30, FC-S-0, and PC-A-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots of FC-S-0 and PC-A, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.35, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The unsubmerged condition plot of FC-S-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.25, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.8, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-S-0 and PC-A begin at approximately the same x-axis and y-axis coordinates, 4 and 1.25, respectively. In rising to the right, the two plots diverge, but not by much. The plot for the FC-S-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-rises most steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively. The plot for the PC-A model-with an 8-inch-radius top bevel and 12-inch corner fillets-rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6.1 and 2.1, respectively. The submerged condition plot for the FC-S-30 model-with 30-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-is a bit lower than the plots for the FC-S-0 and PC-A models. The x-axis and y-axis coordinates of the leftmost point are approximately 4 and 1.2, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 6 and 1.9, respectively. One inch equals 2.54 centimeters.

Figure 49. Sketches. Models tested for effects of multiple barrels.

Sketches. Models tested for effects of multiple barrels. This figure contains sketches and descriptions of 21 culvert entrance models that were tested for the effects of multiple barrels. The 21 models are labeled Figure 49a through 49u. The sketch of each model is a perspective, or three-dimensional, drawing, with the near portion of the model on the left side and the distant portion on the right side. Dimensions are in inches. One inch equals 2.54 centimeters. Here follows a detailed description of each model. Figure 49a shows FC-S-30, a single-barrel model with 30-degree-flared wingwalls, a 4-inch-straight top bevel, no wingwalls bevel, and 6-inch corner fillets. Figure 49b shows FC-S-0, a single-barrel model with 0-degree-flared wingwalls, a 4-inch-straight top bevel, no wingwalls bevel, and 6-inch corner fillets. Figure 49c shows PC-A, a single-barrel model with 0-degree-flared wingwalls, an 8-inch-straight top bevel, a 4-inch-radius wingwalls bevel, and 12-inch corner fillets. Figure 49d shows FC-D-30, a double-barrel model with 30-degree-flared wingwalls, a 4-inch-straight top bevel, no wingwalls bevel, and 6-inch corner fillets. Figure 49e shows FC-D-0, a double-barrel model with 0-degree-flared wingwalls, a 4-inch-straight top bevel, no wingwalls bevel, and 6-inch corner fillets. Figure 49f shows PC-B, a double-barrel model with 0-degree-flared wingwalls, an 8-inch-straight top bevel, a 4-inch-radius wingwalls bevel, and 12-inch corner fillets. Figure 49g shows FC-T-30, a triple-barrel model with 30-degree-flared wingwalls, a 4-inch-straight top bevel, no wingwalls bevel, and 6-inch corner fillets. Figure 49h shows FC-T-0, a triple-barrel model with 0-degree-flared wingwalls, a 4-inch-straight top bevel, no wingwalls bevel, and 6-inch corner fillets. Figure 49i shows PC-C, a triple-barrel model with 0-degree-flared wingwalls, an 8-inch-straight top bevel, a 4-inch-radius wingwalls bevel, and 12-inch corner fillets. Figure 49j shows FC-Q-30, a quad-barrel model with 30-degree-flared wingwalls, a 4-inch-straight top bevel, no wingwalls bevel, and 6-inch corner fillets. Figure 49k shows FC-Q-0, a quad-barrel model with 0-degree-flared wingwalls, a 4-inch-straight top bevel, no wingwalls bevel, and 6-inch corner fillets. Figure 49l shows PC-D, a quad-barrel model with 0-degree-flared wingwalls, an 8-inch-straight top bevel, a 4-inch-radius wingwalls bevel, and 12-inch corner fillets. Figure 49m shows FC-D-30-E, a double-barrel model with 30-degree-flared wingwalls, a 4-inch-straight top bevel, no wingwalls bevel, extended center walls, and 6-inch corner fillets. Figure 49n shows FC-D-0-E, a double-barrel model with 0-degree-flared wingwalls, a 4-inch-straight top bevel, no wingwalls bevel, extended center walls, and 6-inch corner fillets. Figure 49o shows PC-B-E, a double-barrel model with 0-degree-flared wingwalls, an 8-inch-straight top bevel, a 4-inch-radius wingwalls bevel, extended center walls, and 12-inch corner fillets. Figure 49p shows FC-T-30-E, a triple-barrel model with 30-degree-flared wingwalls, a 4-inch-straight top bevel, no wingwalls bevel, extended center walls, and 6-inch corner fillets. Figure 49q shows FC-T-0-E, a triple-barrel model with 0-degree-flared wingwalls, a 4-inch-straight top bevel, no wingwalls bevel, extended center walls, and 6-inch corner fillets. Figure 49r shows PC-C-E, a triple-barrel model with 0-degree-flared wingwalls, an 8-inch-straight top bevel, a 4-inch-radius wingwalls bevel, extended center walls, and 12-inch corner fillets. Figure 49s shows FC-Q-30-E, a quad-barrel model with 30-degree-flared wingwalls, a 4-inch-straight top bevel, no wingwalls bevel, extended center walls, and 6-inch corner fillets. Figure 49t shows FC-Q-0-E, a quad-barrel model with 0-degree-flared wingwalls, a 4-inch-straight top bevel, no wingwalls bevel, extended center walls, and 6-inch corner fillets. Figure 49u shows PC-D-E, a quad-barrel model with 0-degree-flared wingwalls, an 8-inch-straight top bevel, a 4-inch-radius wingwalls bevel, extended center walls, and 12-inch corner fillets.

Figure 50. Graph. Inlet control comparison, field cast 0-degree-flared wingwall models.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Four models-FC-S-0 single, FC-D-0 double, FC-T-0 triple, and FC-Q-0 quad-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. All of the models have 6-inch corner fillets and 0-degree-flared wingwalls. For the unsubmerged condition, the four plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.35, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-D-0 double, FC-T-0 triple, and FC-Q-0 quad are virtually identical. The x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.3, respectively. The plots rise to the right, and the x-axis and y-axis coordinates of the rightmost points are approximately 6 and 2.1, respectively. The plot for FC-S-0 single for the submerged condition starts at approximately the same leftmost point as the other three plots but rises more steeply. Its rightmost point has x-axis and y-axis coordinates of approximately 6 and 2.2, respectively. One inch equals 2.54 centimeters.

Figure 51. Graph. Inlet control comparison, field cast 30-degree-flared wingwall models.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Four models-FC-S-30 single, FC-D-30 double, FC-T-30 triple, and FC-Q-30 quad-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. All of the models have 6-inch corner fillets and 30-degree-flared wingwalls. For the unsubmerged condition, the four plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 0.9, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-D-30 double, FC-T-30 triple, and FC-Q-30 quad are very close. The x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.2, respectively. The plots rise to the right, and the x-axis and y-axis coordinates of the rightmost points are approximately 6 and 2, respectively. The plot of FC-S-0 single for the submerged condition is slightly steeper than the other three plots. The x-axis and y-axis coordinates of its leftmost point are approximately 4 and 1.15, respectively. Its rightmost point has x-axis and y-axis coordinates of approximately 6 and 2, respectively. One inch equals 2.54 centimeters.

Figure 52. Graph. Inlet control comparison, precast models.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Four models-PC-A single, PC-B double, PC-C triple, and PC-D quad-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. All of the models have 12-inch corner fillets and nonextended center walls. For the unsubmerged condition, the four plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.35, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of PC-B double, PC-C triple, and PC-D quad are very close. The x-axis and y-axis coordinates of the leftmost points are approximately 4.1 and 1.35, respectively. The plots rise to the right, and the x-axis and y-axis coordinates of the rightmost points are approximately 6.1 and 1.3, respectively. The plot of PC-A single for the submerged condition is steeper than the other three plots. The x-axis and y-axis coordinates of its leftmost point are approximately 4.1 and 1.3, respectively. Its rightmost point has x-axis and y-axis coordinates of approximately 6.1 and 2.1, respectively. One inch equals 2.54 centimeters.

Figure 53. Graph. Inlet control comparison, single barrel models.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three models-FC-S-30, FC-S-0, and PC-A-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots of FC-S-0 and PC-A, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The unsubmerged condition plot of FC-S-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.8, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-S-0 and PC-A begin at approximately the same x-axis and y-axis coordinates, 4 and 1.25, respectively. In rising to the right, the two plots diverge. The plot for the FC-S-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-rises more steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively. The plot for the PC-A model-with an 8-inch-radius top bevel and 12-inch corner fillets-rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6.1 and 2.1, respectively. The submerged condition plot for the FC-S-30 model-with 30-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-roughly parallels but is lower than the plot for the FC-S-0 model. The x-axis and y-axis coordinates of the leftmost point are approximately 4 and 1.2, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 6 and 1.9, respectively. The vertical distance between the rightmost points of the submerged condition plots for FC-S-0 and FC-S-30 is labeled delta and is approximately 0.3 open parenthesis a dimensionless number close parenthesis. One inch equals 2.54 centimeters.

Figure 54. Graph. Inlet control comparison, double barrel models.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three models-FC-D-30, FC-D-0, and PC-B-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots of FC-D-0 and PC-B, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.35, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The unsubmerged condition plot of FC-D-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.85, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-D-0 and PC-B begin at approximately the same x-axis and y-axis coordinates, 4 and 1.3, respectively. In rising to the right, the two plots diverge. The plot for the FC-D-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-rises more steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.1, respectively. The plot for the PC-B model-with an 8-inch-radius top bevel and 12-inch corner fillets-rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6.1 and 1.7, respectively. The submerged condition plot for the FC-D-30 model-with 30-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-roughly parallels but is lower than the plot for the FC-D-0 model. The x-axis and y-axis coordinates of the leftmost point are approximately 4 and 1.2, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 6 and 1.9, respectively. The vertical distance between the rightmost points of the submerged condition plots for FC-D-0 and FC-D-30 is labeled delta and is approximately 0.2 open parenthesis a dimensionless number close parenthesis. One inch equals 2.54 centimeters.

Figure 55. Graph. Inlet control comparison, triple barrel models.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three models-FC-T-30, FC-T-0, and PC-C-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots of FC-T-0 and PC-C, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The unsubmerged condition plot of FC-T-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.85, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-T-0 and PC-C begin at approximately the same x-axis and y-axis coordinates, 4 and 1.3, respectively. In rising to the right, the two plots diverge. The plot for the FC-T-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-rises more steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.1, respectively. The plot for the PC-C model-with an 8-inch-radius top bevel and 12-inch corner fillets-rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6.1 and 1.9, respectively. The submerged condition plot for the FC-T-30 model-with 30-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-roughly parallels but is lower than the plot for the FC-T-0 model. The x-axis and y-axis coordinates of the leftmost point are approximately 4 and 1.2, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 6 and 2, respectively. The vertical distance between the rightmost points of the submerged condition plots for FC-T-0 and FC-T-30 is labeled delta and is approximately 0.1 open parenthesis a dimensionless number close parenthesis. One inch equals 2.54 centimeters.

Figure 56. Graph. Inlet control comparison, quadruple barrel models.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three models-FC-Q-30, FC-Q-0, and PC-D-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots of FC-Q-0 and PC-D, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The unsubmerged condition plot of FC-Q-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.85, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-Q-0 and PC-D begin at approximately the same x-axis and y-axis coordinates, 4 and 1.3, respectively. In rising to the right, the two plots diverge. The plot for the FC-Q-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-rises more steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.1, respectively. The plot for the PC-D model-with an 8-inch-radius top bevel and 12-inch corner fillets-rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6.1 and 1.8, respectively. The submerged condition plot for the FC-Q-30 model-with 30-degree wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-roughly parallels but is lower than the plot for the FC-Q-0 model. The x-axis and y-axis coordinates of the leftmost point are approximately 4 and 1.2, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 6 and 2, respectively. The vertical distance between the rightmost points of the submerged condition plots for FC-Q-0 and FC-Q-30 is labeled delta and is approximately 0.1 open parenthesis a dimensionless number close parenthesis. One inch equals 2.54 centimeters.

Figure 57. Graph. Inlet control comparison, extended or nonextended center walls, field cast model.

The x-axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-FC-D-30 and FC-D-30-E-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Each model has a double barrel, 6-inch corner fillets, and 30-degree-flared wingwalls. For the unsubmerged condition, the plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 0.8, respectively. For the submerged condition, the two plots, which are in the upper right portion of the graph, are again virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.2, respectively. The x-axis and y-axis coordinates of the rightmost points are approximately 6 and 2, respectively. The FC-D-30 model has nonextended center walls, and FC-D-30-E has extended center walls. One inch equals 2.54 centimeters.

Figure 58. Graph. Inlet control comparison, extended or nonextended center walls, precast model.

The x-axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-PC-B and PC-B-E-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Each model has a double barrel, 8-inch-radius top bevels, and 12-inch corner fillets. For the unsubmerged condition, the plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.6 and 1, respectively. For the submerged condition, the two plots, which are in the upper right portion of the graph, are again virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 4.1 and 1.3, respectively. The x-axis and y-axis coordinates of the rightmost point of PC-B-E, and of both plotted lines, are approximately 6.2 and 2, respectively. The rightmost point of PC-B, with x-axis and y-axis coordinates of approximately 6.2 and 1.8, was assumed to be an outlier and was disregarded in computing the plot for PC-B. The PC-B model has a nonextended center wall, and PC-B-E has an extended center wall. One inch equals 2.54 centimeters.

Figure 59. Sketches. Models tested for effects of span-to-rise ratio.

Sketches. Models tested for effects of span-to-rise ratio. This figure contains sketches and descriptions of 12 culvert entrance models that were tested for the effects of the span-to-rise ratio. The 12 models are in three columns of four each. The sketch of each model is a perspective, or three-dimensional, drawing, with the near portion of the model on the left side and the distant portion on the right side. Dimensions are in inches. One inch equals 2.54 centimeters. The first column has four FC-S-30 models, labeled 59a through 59d, with the following common characteristics: 30-degree-flared wingwalls, a 4-inch-straight top bevel, no wingwalls bevel, and no corner fillets. The four models differ in the span-to-rise ratio. In figure 59a the ratio is 1 to 1. In figure 59b the ratio is 2 to 1. In figure 59c the ratio is 3 to 1. In figure 59d the ratio is 4 to 1. The second column has four FC-S-0 models, labeled 59e through 59h, with the following common characteristics: 0-degree-flared wingwalls, a 4-inch-straight top bevel, no wingwalls bevel, and no corner fillets. The four models differ in the span-to-rise ratio. In figure 59e the ratio is 1 to 1. In figure 59f the ratio is 2 to 1. In figure 59g the ratio is 3 to 1. In figure 59h the ratio is 4 to 1. The third column has four PC-A models. Labeled 59i through 59l, with the following common characteristics: 0-degree-flared wingwalls, an 8-inch-straight top bevel, a 4-inch-radius wingwalls bevel, and no corner fillets. The four models differ in the span-to-rise ratio. In figure 59i the ratio is 1 to 1. In figure 59j the ratio is 2 to 1. In figure 59k the ratio is 3 to 1. In figure 59l the ratio is 4 to 1.

Figure 60. Graph. Inlet control comparison, FC-S-0 span-to-rise ratios.

The x-axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Four FC-S-0 models are plotted. The models differ in their span-to-rise ratios: 1:1, 2:1, 3:1, and 4:1. Each model has no corner fillets and 0-degree-flared wingwalls. The plots are for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots, which are in the lower left corner of the graph, are very close but do show a small loss in performance-evidenced by slightly higher plots-as the span-to-rise ratio increases. The plots rise from left to right. The x-axis coordinates of the leftmost points are approximately 0.5. The y-axis coordinates of the leftmost points range from approximately 0.35 to 0.4, with the leftmost point of the 1:1 span-to-rise plot being the lowest. The x axis coordinates of the rightmost points are approximately 2.5. The y-axis coordinates of the rightmost points range from approximately 1 to 1.05, with the rightmost point of the 1:1 span-to-rise plot being the lowest. For the submerged condition, the four plots, which are in the upper right portion of the graph, are very close. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.35, respectively, except that the y-axis coordinate of the leftmost point of the 1:1 span-to-rise plot is approximately 1.25. The x-axis and y-axis coordinates of the rightmost points of all four plots are approximately 6 and 2.2, respectively.

Figure 61. Graph. Inlet control comparison, PC-A span-to-rise ratios.

The x-axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Four PC-A models are plotted. The models differ in their span-to-rise ratios: 1:1, 2:1, 3:1, and 4:1. Each model has no corner fillets and an 8-inch-radius top bevel. One inch equals 2.54 centimeters. The plots are for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots, which are in the lower left corner of the graph, are very close but do show a small loss in performance-evidenced by slightly higher plots-as the span-to-rise ratio increases. The plots rise from left to right. The x-axis coordinates of the leftmost points are approximately 0.5. The y-axis coordinates of the leftmost points range from approximately 0.35 to 0.4, with the leftmost point of the 1:1 span-to-rise plot being the lowest. The x axis coordinates of the rightmost points are approximately 2.5. The y-axis coordinates of the rightmost points range from approximately 1 to 1.05, with the rightmost point of the 1:1 span-to-rise plot being the lowest. For the submerged condition, the four plots, which are in the upper right portion of the graph, are very close. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.35, respectively, except that the y-axis coordinate of the leftmost point of the 1:1 span-to-rise plot is approximately 1.25. The x-axis and y-axis coordinates of the rightmost points of all four plots are approximately 6 and 2, respectively.

Figure 62. Graph. Inlet control comparison, FC-S-30 span-to-rise ratios.

The x-axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Four FC-S-30 models are plotted. The models differ in their span-to-rise ratios: 1:1, 2:1, 3:1, and 4:1. Each model has no corner fillets and 30-degree-flared wingwalls. The plots are for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 0.9, respectively. For the submerged condition, the plots show a decrease in performance-evidenced by higher plots-as the span-to-rise ratio increases. The lowest plot is for the 1:1 span-to-rise ratio. The x-axis and y-axis coordinates of its leftmost point are 4 and 1.1, respectively. The x-axis and y-axis coordinates of its rightmost point are 6 and 1.9, respectively. The highest plot is for the 4:1 span-to-rise ratio. The x-axis and y-axis coordinates of its leftmost point are 4 and 1.25, respectively. The x-axis and y-axis coordinates of its rightmost point are 6 and 2.05, respectively.

Figure 63. Graph. Inlet control comparison, 1:1 span-to-rise ratio.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three models-FC-S-0, FC-S-30, and PC-A-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. The span-to-rise ratio of each model is 1:1. For the unsubmerged condition, the plots of FC-S-0 and PC-A, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The unsubmerged condition plot of FC-S-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.25, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.8, respectively. For the submerged condition, which is in the upper right portion of the graph, each model has a unique plot, all of which rise to the right. The plot of the FC-S-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and no corner fillets-begins at x-axis and y-axis coordinates of approximately 4 and 1.25, respectively. The plot ends at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively. The submerged condition plot for the PC-A model-with an 8-inch-radius top bevel and no corner fillets-begins at x-axis and y-axis coordinates of approximately 4 and 1.3, respectively. The plot ends at x-axis and y-axis coordinates of approximately 6 and 2, respectively. The submerged condition plot for the FC-S-30 model-with 30-degree-flared wingwalls, a 4-inch-straight top bevel, and no corner fillets-begins at x-axis and y-axis coordinates of approximately 4 and 1.1, respectively. The plot ends at x-axis and y-axis coordinates of approximately 6 and 1.9, respectively. The vertical distance between the rightmost points of the submerged condition plots for FC-S-0 and FC-S-30 is labeled delta and is approximately 0.3 open parenthesis a dimensionless number close parenthesis. One inch equals 2.54 centimeters.

Figure 64. Graph. Inlet control comparison, 2:1 span-to-rise ratio.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three models-FC-S-0, FC-S-30, and PC-A-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. The span-to-rise ratio of each model is 2:1. For the unsubmerged condition, the plots of FC-S-0 and PC-A, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The unsubmerged condition plot of FC-S-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.25, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.8, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-S-0 and PC-A begin at approximately the same x-axis and y-axis coordinates, 4 and 1.3, respectively. In rising to the right, the two plots diverge. The plot for the FC-S-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and no corner fillets-rises more steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively. The plot for the PC-A model-with an 8-inch-radius top bevel and no corner fillets-rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6 and 2, respectively. The submerged condition plot for the FC-S-30 model-with 30-degree-flared wingwalls, a 4-inch-straight top bevel, and no corner fillets-begins at x-axis and y-axis coordinates of approximately 4 and 1.2, respectively. The plot ends at x-axis and y-axis coordinates of approximately 6 and 2, respectively. The vertical distance between the rightmost points of the submerged condition plots for FC-S-0 and FC-S-30 is labeled delta and is approximately 0.2 open parenthesis a dimensionless number close parenthesis. One inch equals 2.54 centimeters.

Figure 65. Graph. Inlet control comparison, 3:1 span-to-rise ratio.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three models-FC-S-0, FC-S-30, and PC-A-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. The span-to-rise ratio of each model is 3:1. For the unsubmerged condition, the plots of FC-S-0 and PC-A, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The unsubmerged condition plot of FC-S-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.25, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.8, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-S-0 and PC-A begin at approximately the same x-axis and y-axis coordinates, 4 and 1.3, respectively. In rising to the right, the two plots diverge. The plot for the FC-S-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and no corner fillets-rises more steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively. The plot for the PC-A model-with an 8-inch-radius top bevel and no corner fillets-rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6 and 2, respectively. The submerged condition plot for the FC-S-30 model-with 30-degree-flared wingwalls, a 4-inch-straight top bevel, and no corner fillets-begins at x-axis and y-axis coordinates of approximately 4 and 1.2, respectively. The plot ends at x-axis and y-axis coordinates of approximately 6 and 2.05, respectively. The vertical distance between the rightmost points of the submerged condition plots for FC-S-0 and FC-S-30 is labeled delta and is approximately 0.15 open parenthesis a dimensionless number close parenthesis. One inch equals 2.54 centimeters.

Figure 66. Graph. Inlet control comparison, 4:1 span-to-rise ratio.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three models-FC-S-0, FC-S-30, and PC-A-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. The span-to-rise ratio of each model is 4:1. For the unsubmerged condition, the plots of FC-S-0 and PC-A, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.45, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1.05, respectively. The unsubmerged condition plot of FC-S-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.85, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-S-0 and PC-A begin at approximately the same x-axis and y-axis coordinates, 4 and 1.35, respectively. In rising to the right, the two plots diverge. The plot for the FC-S-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and no corner fillets-rises more steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively. The plot for the PC-A model-with an 8-inch-radius top bevel and no corner fillets-rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6 and 2, respectively. The submerged condition plot for the FC-S-30 model-with 30-degree-flared wingwalls, a 4-inch-straight top bevel, and no corner fillets-begins at x-axis and y-axis coordinates of approximately 4 and 1.25, respectively. The plot ends at x-axis and y-axis coordinates of approximately 6 and 2.05, respectively. The vertical distance between the rightmost points of the submerged condition plots for FC-S-0 and FC-S-30 is labeled delta and is approximately 0.15 open parenthesis a dimensionless number close parenthesis. One inch equals 2.54 centimeters.

Figure 67. Diagram. Definition sketch for skew tests.

The figure is a diagram, from an overhead perspective, of a road and a culvert. The road alignment is vertical in the figure, or straight up and down. The culvert goes under the road at an angle. The culvert entrance is on the lower left, and the culvert exit is at the upper right. An arrow on the left side of the diagram indicates the direction of flow. The direction of flow is identical to the direction of the culvert. On the left side of the diagram, the angle between the direction of flow and a dotted line perpendicular to the direction of the road is labeled skew.

Figure 68. Sketches. Models tested for effects of headwall skew.

Sketches. Models tested for effects of headwall skew. This figure contains sketches and descriptions, in two rows, of six culvert entrance models that were tested for the effects of headwall skew. The sketch of each model is a perspective, or three-dimensional, drawing, with the near portion of the model on the left side and the distant portion on the right side. Dimensions are in inches. One inch equals 2.54 centimeters. The first row contains 4 FC-T-30 models, labeled figure 68a through 68d. Each model is triple barrel and has 30-degree-flared wingwalls, 4-inch-straight top bevels, no wingwalls bevel, and no corner fillets. The four models differ only in their skew. In figure 68a, the skew is 0 degrees. In figure 68b, the skew is 15 degrees. In figure 68c, the skew is 30 degrees. In figure 68d, the skew is 45 degrees. The second row contains 2 FC-S-30 models, labeled figure 68e and 68f. Each model is single barrel and has 30-degree-flared wingwalls, a 4-inch-straight top bevel, no wingwalls bevel, a 3:1 span-to-rise ratio, and no corner fillets. The two models differ only in their skew. In figure 68e the skew is 0 degrees. In figure 68f the skew is 30 degrees.

Figure 69. Diagrams. Plan view of skewed headwall models tested.

Diagrams. Plan view of skewed headwall models tested. The figure consists of four diagrams, from an overhead perspective, of a road and a culvert. The diagrams, labeled 69a through 69d, are in two rows of two each. The culvert in each case is an FC-T-30 model. Figure 69a, in the upper left, is of 0-degree skew. The direction of the culvert is perpendicular to the road alignment, which is horizontal. The angles between the direction of the culvert and the flared wingwalls at each side of the entrance are 30 degrees and 30 degrees, respectively. Figure 69b, in the upper right, is of 15-degree skew. The direction of the culvert is at a slight angle, presumably 15 degrees, to the road alignment, which rises gently from left to right. The angles between the direction of the culvert and the flared wingwalls at each side of the entrance are 10 degrees and 30 degrees, respectively. Figure 69c, in the lower left, is of 30-degree skew. The direction of the culvert is at a modest angle, presumably 30 degrees, to the road alignment, which rises from left to right. The angles between the direction of the culvert and the flared wingwalls at each side of the entrance are 15 degrees and 30 degrees, respectively. Figure 69d, in the lower right, is of 45-degree skew. The direction of the culvert is at an angle, presumably 45 degrees, to the road alignment, which rises sharply from left to right. The angles between the direction of the culvert and the wingwalls at each side of the entrance are 0 degrees and 35 degrees, respectively.

Figure 70. Graph. Inlet control comparison, skew angles.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Five models are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Four of the models are FC-T-30, differing only in their skew: 0, 15, 30, and 45 degrees. The FC-T-30 models are triple barrel and have no corner fillets. The fifth model is HDS-5 12 slash 3 and has skew approximation of 15 to 45 degrees. For the unsubmerged condition, the FC-T-30 plots for 15, 30, and 45 degrees, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.5, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1.1, respectively. The unsubmerged condition plots for FC-T-30 at 0 skew and for HDS-5 12 slash 3 are also in the lower left corner of the graph but a bit lower. For FC-T-30 at 0 skew, the x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.3, respectively; the x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.8, respectively. For HDS-5 12 slash 3, the x-axis and y-axis coordinates of the leftmost point are approximately 1.5 and 0.6, respectively; the x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.8, respectively. For the submerged condition, which is in the upper right portion of the graph, the FC-T-30 plots for 15, 30, and 45 degrees are similar and rise to the right. The three plots begin at x-axis and y-axis coordinates of approximately 4 and 1.9, respectively. The x-axis coordinates of the rightmost points are approximately 6. The y-axis coordinates of the rightmost points range approximately from 1.9 to 2.1. The submerged condition plots for FC-T-30 at 0 skew and for HDS-5 12 slash 3 are also in the upper right portion of the graph and also rise to the right. For FC-T-30 at 0 skew, the x-axis and y-axis coordinates of the leftmost point are approximately 4 and 1.2, respectively; the x axis and y-axis coordinates of the rightmost point are approximately 6 and 2, respectively. For HDS-5 12 slash 3, the x-axis and y-axis coordinates of the leftmost point are approximately 4 and 1.2, respectively; the x axis and y-axis coordinates of the rightmost point are approximately 6 and 2.1, respectively.

Figure 71. Graph. Entrance loss coefficients versus the Reynolds number, HDS-5 8 slash 3.

The x-axis is HW divided by D, which is a dimensionless ratio, and ranges from 0 to 4. The y-axis is the entrance loss coefficient K subscript e, which is also dimensionless, and ranges from 0 to 1.4. Nine sets of entrance loss coefficients are plotted. Each set has a Reynolds number open parenthesis a dimensionless number close parenthesis. The Reynolds numbers are: 65,000, 81,000, 130,000, 146,000, 162,000, 178,000, 194,000, 227,000, and 260,000. The plotted points are between approximately 1 and 3.75 on the x-axis and approximately 0.6 and 1 on the y-axis. The plotted points with low Reynolds numbers are generally more scattered and in the lower portion of the x-axis range.

Figure 72. Graph. Standard deviation of K subscript e versus the Reynolds number.

The x-axis is the Reynolds number open parenthesis a dimensionless number close parenthesis and ranges from 50,000 to 300,000. The y-axis is the standard deviation open parenthesis also a dimensionless number close parenthesis and ranges from 0.00 to 0.16. Nine points are plotted. Each point is the standard deviation of one of the nine sets of entrance loss coefficients plotted in figure 71. Each of the nine sets in figure 71 has a Reynolds number. Consequently, each of the points in figure 72 is associated with a Reynolds number. A trend line is fitted through the nine points. The line is roughly a decreasing exponential function. The x-axis and y-axis coordinates of the leftmost edge of the line are approximately 65,000 and 0.14 respectively. The x-axis and y-axis coordinates of the rightmost edge of the line are approximately 260,000 and 0.04, respectively. The point for the standard deviation of the set of entrance loss coefficients with the Reynolds number of 162,000 is something of an outlier, being well above the trend line.

Figure 73. Diagram. Culvert contraction.

This two-dimensional figure shows the contraction and subsequent expansion of flow entering a culvert. The left side of the diagram is the approach area to the culvert and is labeled A subscript lowercase a. Shortly after entering the culvert, the flow reaches its narrowest point, which is labeled contracted area A subscript c. As the flow continues through the culvert, it expands to occupy the full culvert area, which is labeled A. In terms of size, A subscript lowercase a is the largest area and A subscript c is the smallest.

Figure 74. Equation. Expansion loss equation.

H subscript L-e equals H subscript Lc, which in turn is equal to three alternatives. The first alternative is the product of two terms. The first term is the square of the difference between the quotient of A divided by A subscript c, all minus 1. The second term is the quotient of V squared divided by the product of 2 times g. The second alternative is also the product of two terms. The first term is the square of the difference between the quotient of A divided by the product of C subscript c times A, all minus 1. The second term is the quotient of V squared divided by the product of 2 times g. The third alternative is again the product of two terms. The first term is the square of the difference between the quotient of 1 divided by the product of C subscript c, all minus 1. The second term is the quotient of V squared divided by the product of 2 times g.

Figure 75. Equation. Exit loss, with coefficient of 1.

H subscript L-o equals the product of 1 times the difference between two quotients. The first quotient is V squared divided by the product of 2 times g. From this quotient is subtracted the second quotient, which is V subscript lowercase d, all squared, divided by the product of 2 times g.

Figure 76. Equation. Downstream velocity.

V subscript lowercase d equals the quotient of Q divided by the product of W subscript TB times T W.

Figure 77. Equation. Exit loss, with coefficient K subscript o.

H subscript L-o equals the product of K subscript o times the difference between two quotients. The first quotient is V squared divided by the product of 2 times g. From this quotient is taken the second quotient, which is V subscript lowercase d, all squared, divided by the product of 2 times g.

Figure 78. Diagram. Flow expansion in the tailbox for high tailwater.

The figure is a two-dimensional overhead perspective of a portion of the experimental setup. The portion is the tailbox area at the culvert's exit. The culvert's exit is on the left side of the figure. The culvert's width is labeled B. The tailbox is an open-ended rectangle, with the open end being downstream, which is on the right side of the figure. The tailbox is wider than the culvert, with equal portions of the tailbox's wider width being on each side of the culvert's exit. Five pressure ports are located in a left-to-right line in the center of the tailbox. A dotted line begins near each side of the culvert's exit. The two dotted lines become further apart as the distance from the culvert's exit increases. The dotted lines represent the area of the flow exiting the culvert. The horizontal length of each dotted line is approximately 3B, or three times the width of the culvert. The angle of the flow's flare, or the angle between the dotted line and the horizontal, is 5.6 degrees. Three velocity profiles are shown in the tailbox area. The velocity profiles indicate different velocities in the flow at a particular point in the tailbox area. Velocity profile 1 is just to the right of the culvert's exit. The maximum velocity is 65.2 centimeters per second. The slower velocities are near the edges of the flow and in the middle. Velocity profile 2 is approximately halfway to the 3B distance, and past the second pressure port. The maximum velocity is 57.1 centimeters per second. The slower velocities are near the edges of the flow. Velocity profile 3 is at the 3B distance, and past the fifth pressure port. The maximum velocity is 43.3 centimeters per second. The slower velocities are near the edges of the flow.

Figure 79. Diagram. Flow expansion in the tailbox for low tailwater.

The figure is a two-dimensional overhead perspective of a portion of the experimental setup. The portion is the tailbox area at the culvert's exit. The culvert's exit is on the left side of the figure. The culvert's width is labeled B. The tailbox is an open-ended rectangle, with the open end being downstream, which is on the right side of the figure. The tailbox is wider than the culvert, with equal portions of the tailbox's wider width being on each side of the culvert's exit. Five pressure ports are located in a left-to-right line in the center of the tailbox. A dotted line begins near each side of the culvert's exit. The two dotted lines become further apart as the distance from the culvert's exit increases. The dotted lines represent the area of the flow exiting the culvert. The horizontal length of each dotted line is approximately 3B, or three times the width of the culvert. The angle of the flow's flare, or the angle between the dotted line and the horizontal, is 6.0 degrees. Three velocity profiles are shown in the tailbox area. The velocity profiles indicate different velocities in the flow at a particular point in the tailbox area. Velocity profile 1 is just to the right of the culvert's exit. The maximum velocity is 143.7 centimeters per second. The slower velocities are near the edges of the flow and in the middle. Velocity profile 2 is approximately halfway to the 3B distance, and past the second pressure port. The maximum velocity is 95.1 centimeters per second. The slower velocities are near the edges of the flow. Velocity profile 3 is at the 3B distance, and past the fifth pressure port. The maximum velocity is 76.8 centimeters per second. The slower velocities are near the edges of the flow.

Figure 80. Diagram. Vertical flow expansion in the tailbox and projected E G L.

The figure is a two-dimensional side perspective of a portion of the experimental setup. The portion is the tailbox at the culvert's exit. The culvert's exit is on the left side of the figure. The tailbox is a rectangle and larger than the culvert. Five pressure ports are located in a left-to-right line on the bottom of the tailbox. The depth of the tailwater in the tailbox is labeled T w. The tailwater's surface, which is the H G L, is above the culvert's exit. Dotted lines within the tailwater indicate the flow from the culvert's exit. As it moves to the right, the flow spreads upward toward the H G L and downward to the bottom of the tailbox. The angle of the flow's upward movement is 4.2 degrees, and the angle of its downward movement is 8.0 degrees. Six velocity profiles are shown in the tailwater. Above the tailwater or on its upper surface, directly above each pressure port, is a point on a hypothetical E G L that is projected to the culvert outlet plane. As suggested in the text, the point could be calculated from the flow velocities. The E G L slopes slightly downward from left to right. The distance between the E G L and the H G L is the quotient of V subscript D, all squared, divided by the product of 2 times g. On the left side of the tailbox, the distance the E G L drops as it enters the tailbox is labeled H subscript L-o.

Figure 81. Graph. Transition area, unsubmerged and submerged inlet flow conditions.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. One model is plotted. The model is FC-S-0 with a single barrel and no corner fillets. The plot is divided into three sections: unsubmerged regression data, a transition area, and submerged regression data. For the section of unsubmerged regression data, the x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.3, respectively; the x-axis and y-axis coordinates of the rightmost point are approximately 2.3 and 0.9, respectively. For the transition area, where the plotted line is predicted by fifth-order polynomials, the x-axis and y-axis coordinates of the leftmost edge are approximately 2.3 and 0.9, respectively; the x-axis and y-axis coordinates of the rightmost edge are approximately 4 and 1.3, respectively. For the section of submerged regression data, the x-axis and y-axis coordinates of the leftmost point are approximately 4 and 1.3, respectively; the x-axis and y-axis coordinates of the rightmost point are approximately 5.8 and 2.1, respectively.

Figure 82. Equation. Transition area, unsubmerged and submerged inlet flow conditions.

The quotient H W subscript i divided by D equals the sum of six terms. The first term is lowercase a. The second term is the product of b times the quotient of Q divided by the product of A times D to the power of 0.5. The third term is the product of c times the quotient to the power of 2 of Q divided by the product of A times D to the power of 0.5. The fourth term is the product of lowercase d times the quotient to the power of 3 of Q divided by the product of A times D to the power of 0.5. The fifth term is the product of e times the quotient to the power of 4 of Q divided by the product of A times D to the power of 0.5. The sixth term is the product of f times the quotient to the power of 5 of Q divided by the product of A times D to the power of 0.5.

Figure 83. Graph. PC and FC single barrel models parenthesis sketches 1, 7, 11 in figure 93 end parenthesis.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three single barrel models-FC-S-30, FC-S-0, and PC-A-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots of FC-S-0 and PC-A, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The unsubmerged condition plot of FC-S-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.85, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-S-0 and PC-A begin at approximately the same x-axis and y-axis coordinates, 4 and 1.3, respectively. In rising to the right, the two plots diverge. The plot for the FC-S-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-rises more steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively. The plot for the PC-A model-with an 8-inch-radius top bevel and 12-inch corner fillets-rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6.2 and 2.1, respectively. The submerged condition plot for the FC-S-30 model-with 30-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-begins at x-axis and y-axis coordinates of approximately 4 and 1.2, respectively. The plot ends at x-axis and y-axis coordinates of approximately 6 and 2, respectively. One inch equals 2.54 centimeters.

Figure 84. Graph. PC and FC multiple barrel models parenthesis sketches 1, 2, 7, 8, 11, 12 in figure 93 end parenthesis.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three multiple barrel models-FC-0, FC-30, and PC-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Each plot is a result of combining double, triple, and quad barrel versions of that particular model. For the unsubmerged condition, the plots of FC-0 and PC, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The unsubmerged condition plot of FC-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.85, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-0 and PC begin at approximately the same x-axis and y-axis coordinates, 4 and 1.3, respectively. In rising to the right, the two plots diverge. The plot for the FC-0 model-with 0-degree-flared wingwalls and 6-inch corner fillets-rises more steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.1, respectively. The plot for the PC model-with an 8-inch-radius top bevel and 12-inch corner fillets-rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6.2 and 1.8, respectively. The submerged condition plot for the FC-30 model-with 30-degree-flared wingwalls and 6-inch corner fillets-begins at x-axis and y-axis coordinates of approximately 4 and 1.25, respectively. The plot ends at x-axis and y-axis coordinates of approximately 6 and 2, respectively. One inch equals 2.54 centimeters.

Figure 85. Graph. Combined corner fillet data, FC-S-0 and PC-A models parenthesis sketches 7, 10, 11, 14 in figure 93 end parenthesis.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-FC-S-0 and PC-A-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Each model has a single barrel, and for plotting purposes the 0-, 6-, and 12-inch corner fillets versions are combined. For the unsubmerged condition, the two plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. For the submerged condition, which is in the upper right portion of the graph, the two plots begin at approximately the same x-axis and y-axis coordinates, 4 and 1.25, respectively. In rising to the right, the two plots diverge. The plot for the FC-S-0 model-with 0-degree-flared wingwalls-rises more steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively. The plot for the PC-A model-with an 8-inch-radius top bevel-rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6 and 2, respectively. One inch equals 2.54 centimeters.

Figure 86. Graph. Combined multiple barrel data, FC-0 models parenthesis sketches 7, 8 in figure 93 end parenthesis.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. The graph contains two plots, one for the single barrel FC-S-0 model and one that combines the double, triple, and quad barrel versions of the FC-0 model. The plots are for two conditions: inlet control unsubmerged and inlet control submerged. All of the models have 0-degree-flared wingwalls and 6-inch corner fillets. One inch equals 2.54 centimeters. For the unsubmerged condition, the two plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. For the submerged condition, which is in the upper right portion of the graph, the two plots begin at approximately the same x-axis and y-axis coordinates, 4 and 1.25, respectively. In rising to the right, the two plots diverge. The plot for the FC-S-0 single barrel model rises more steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively. The plot for the combined multiple barrel FC-0 models rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6 and 2.1, respectively.

Figure 87. Graph. Combined multiple barrel data, FC-30 models parenthesis sketches 1, 2 in figure 93 end parenthesis.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. The graph contains two plots, one for the single barrel FC-S-30 model and one that combines the double, triple, and quad barrel versions of the FC-30 model. The plots are for two conditions: inlet control unsubmerged and inlet control submerged. All of the models have 30-degree-flared wingwalls and 6-inch corner fillets. One inch equals 2.54 centimeters. For the unsubmerged condition, the two plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 0.9, respectively. For the submerged condition, which is in the upper right portion of the graph, the two plots begin at approximately the same x-axis coordinate, 4. For the y-axis coordinate, the beginning point for the single barrel plot is approximately 1.2, and the beginning point for the multiple barrel plot is approximately 1.25. In rising to the right, the two plots converge, ending at x-axis and y-axis coordinates of approximately 6 and 2, respectively.

Figure 88. Graph. Combined multiple barrel data, PC models parenthesis sketches 11, 12 in figure 93 end parenthesis.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. The graph contains two plots, one for the single barrel PC-A model and one that combines the double, triple, and quad barrel versions of the PC model. The plots are for two conditions: inlet control unsubmerged and inlet control submerged. All of the models have 8 inch-radius top bevels and 12-inch corner fillets. One inch equals 2.54 centimeters. For the unsubmerged condition, the two plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. For the submerged condition, which is in the upper right portion of the graph, the two plots begin at approximately the same x-axis and y-axis coordinates, 4.1 and 1.25, respectively. In rising to the right, the two plots diverge. The plot for the PC-A single barrel model rises more steeply, ending at x-axis and y-axis coordinates of approximately 6.2 and 2.05, respectively. The plot for the combined multiple barrel PC models rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6.2 and 1.8, respectively.

Figure 89. Graph. Combined span-to-rise data, FC-S-0 models parenthesis sketches 7, 9 in figure 93 end parenthesis.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. The graph contains two plots, one for the 1-to-1 span-to-rise FC-S-0 model and one that combines the 2-to-1, 3-to-1, and 4-to-1 span-to-rise versions of the FC-S-0 model. The plots are for two conditions: inlet control unsubmerged and inlet control submerged. All of the models have 0-degree-flared wingwalls and no corner fillets. For the unsubmerged condition, the two plots, which are in the lower left corner of the graph, are very close together. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. For the submerged condition, which is in the upper right portion of the graph, the two plots begin at approximately the same x-axis coordinate, 4. For the y-axis coordinate, the beginning point for the 1-to-1 span-to-rise plot is approximately 1.25, and the beginning point for the combined plot is approximately 1.3. In rising to the right, the two plots converge, ending at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively.

Figure 90. Graph. Combined span-to-rise data, FC-S-30 models parenthesis sketches 1, 3 in figure 93 end parenthesis.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. The graph contains two plots, one for the 1:1 span-to-rise FC-S-30 model and one that combines the 2-to-1, 3-to-1, and 4-to-1 span-to-rise versions of the FC-S-30 model. The plots are for two conditions: inlet control unsubmerged and inlet control submerged. All of the models have 30-degree-flared wingwalls and no corner fillets. For the unsubmerged condition, the two plots, which are in the lower left corner of the graph, are very close together. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.25, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 0.85, respectively. For the submerged condition, which is in the upper right portion of the graph, the 1-to-1 span-to-rise plot begins at x-axis and y-axis coordinates of approximately 4 and 1.1, respectively; the plot ends at x-axis and y-axis coordinates of approximately 6 and 1.9, respectively. The combined span-to-rise plot begins at x-axis and y-axis coordinates of approximately 4 and 1.2, respectively; the plot ends at x-axis and y-axis coordinates of approximately 6 and 2, respectively.

Figure 91. Graph. Combined span-to-rise data, PC-A models parenthesis sketches 10, 13 in figure 93 end parenthesis.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. The graph contains two plots, one for the 1-to-1 span-to-rise PC-A model and one that combines the 2-to-1, 3-to-1, and 4-to-1 span-to-rise versions of the PC-A model. The plots are for two conditions: inlet control unsubmerged and inlet control submerged. All of the models have 8-inch-radius top bevels and no corner fillets. One inch equals 2.54 centimeters. For the unsubmerged condition, the two plots, which are in the lower left corner of the graph, are very close together. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. For the submerged condition, which is in the upper right portion of the graph, the two plots begin at approximately the same x-axis coordinate, 4. For the y-axis coordinate, the beginning point for the 1-to-1 span-to-rise plot is approximately 1.25, and the beginning point for the combined plot is approximately 1.35. In rising to the right, the two plots converge, ending at x-axis and y-axis coordinates of approximately 6 and 2, respectively.

Figure 92. Graph. Skewed and nonskewed headwalls, FC-T-30 models parenthesis sketches 4, 5 in figure 93 end parenthesis.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. The graph contains two plots, one for the FC-T-30 model with no headwall skew and one that combines the results of 15-, 30-, and 45-degree headwall skews of the FC-T-30 model. The plots are for two conditions: inlet control unsubmerged and inlet control submerged. All of the models have no corner fillets and 30-degree-flared wingwalls. For the unsubmerged condition, the two plots, which are in the lower left corner of the graph, rise from left to right. The leftmost point for the plot for the no skew headwall has x-axis and y-axis coordinates of approximately 0.5 and 0.3, respectively; the x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.9, respectively. The leftmost point for the plot for the combined headwall skews has x-axis and y-axis coordinates of approximately 0.5 and 0.5, respectively; the x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 1.1, respectively. For the submerged condition, which is in the upper right portion of the graph, the two plots begin at approximately the same x-axis coordinate, 4. For the y-axis coordinate, the beginning point for the no headwall skew plot is approximately 1.2, and the beginning point for the combined headwall skews plot is approximately 1.9. In rising to the right, the two plots converge, ending at x-axis and y-axis coordinates of approximately 6 and 2, respectively.

Figure 93. Sketches. Thumbnail sketches of inlets recommended for implementation.

Thumbnail sketches of inlets recommended for implementation. This figure contains fourteen sketches of inlets for box culverts, labeled as figure 93a, sketch 1, through 93n, sketch 14. Each sketch contains one or more drawings of inlets. Each drawing is a perspective, or three-dimensional, drawing, with the near portion of the model on the left side and the distant portion on the right side. Here follows a description of each sketch. Figure 93a, sketch 1, contains one drawing of an inlet. The inlet is a single barrel with 30-degree-flared wingwalls and the top edge beveled at 45 degrees. Figure 93b, sketch 2, contains three drawings of inlets. The inlets have 30-degree-flared wingwalls and the top edges beveled at 45 degrees. The first inlet has two barrels; the second has three; and the third has four. Figure 93c, sketch 3, contains three drawings of inlets. The inlets have 30-degree-flared wingwalls, the top edges beveled at 45 degrees, and single barrels. The first inlet has a 1-to-1 span-to-rise ratio; the second has a 2-to-1 span-to-rise ratio; and the third has a 3-to-1 span-to-rise ratio. Figure 93d, sketch 4, contains one drawing of an inlet. The inlet has three barrels, 30-degree-flared wingwalls, top edges beveled at 45 degrees, and a headwall skewed 15 degrees. Figure 93e, sketch 5, contains two drawings of inlets. The inlets have three barrels, 30-degree-flared wingwalls, and top edges beveled at 45 degrees. The first inlet has a headwall skewed 30 degrees; the second has a headwall skewed 45 degrees. Figure 93f, sketch 6, contains one drawing of an inlet. The inlet has a single barrel, 0-degree-flared wingwalls, and a square-edged crown. Figure 93g, sketch 7, contains two drawings of inlets. The inlets have single barrels, 0-degree-flared wingwalls that are extended, and top edges beveled at 45 degrees. The first inlet has no corner fillets; the second has 6-inch corner fillets. Figure 93h, sketch 8, contains three drawings of inlets. The inlets have 0-degree-flared wingwalls that are extended and top edges beveled at 45 degrees. The first inlet has two barrels; the second has three; and the third has four. Figure 93i, sketch 9, contains three drawings of inlets. The inlets have single barrels, 0-degree-flared wingwalls that are extended, and top edges beveled at 45 degrees. The first inlet has a 1-to-1 span-to-rise ratio; the second has a 2-to-1 span-to-rise ratio; and the third has a 3-to-1 span-to-rise ratio. Figure 93j, sketch 10, contains two drawings of inlets. The inlets have single barrels, 0-degree-flared wingwalls that are extended, and crowns rounded at an 8-inch radius. The first inlet has no corner fillets; the second has 6-inch corner fillets. Figure 93k, sketch 11, contains one drawing of an inlet. The inlet has a single barrel, 0-degree-flared wingwalls that are extended, a crown rounded at an 8-inch radius, and 12-inch corner fillets. Figure 93l, sketch 12, contains three drawings of inlets. The inlets have 0-degree-flared wingwalls that are extended, crowns rounded at an 8-inch radius, and 12-inch corner fillets. The first inlet has two barrels; the second has three barrels, with an extended wall between the second barrel and the rightmost barrel; and the third has four barrels, with an extended wall between the two barrels in the center. Figure 93m, sketch 13, contains three drawings of inlets. The inlets have single barrels, 0-degree-flared wingwalls that are extended, crowns rounded at an 8-inch radius, and 12-inch corner fillets. The first inlet has a 1-to-1 span-to-rise ratio; the second has a 2-to-1 span-to-rise ratio; and the third has a 3-to-1 span-to-rise ratio. Figure 93n, sketch 14, contains one drawing of an inlet. The inlet has a single barrel, 0-degree-flared wingwalls that are extended, a top edge beveled at 45 degrees, and 12-inch corner fillets.

Figure 94. Graph. Inlet control, FD-S-0 and PC-A, no corner fillets.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models are plotted, the FC-S-0 model with no corner fillets and a 4-inch-straight top bevel, and the PC-A model with no corner fillets and an 8-inch-radius bevel. One inch equals 2.54 centimeters. The plots are for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the two plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. For the submerged condition, which is in the upper right portion of the graph, the two plots begin at approximately the same x-axis and y-axis coordinates, 4 and 1.25, respectively. In rising to the right, the two plots diverge. The plot for the FC-S-0 model rises more steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively. The plot for the PC-A model rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6 and 2, respectively.

Figure 95. Graph. Inlet control, FC-S-0 and PC-A, 6-inch corner fillets.

The x-axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-FC-S-0 and PC-A-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. For the submerged condition, the two plots, which are in the upper right portion of the graph, begin at approximately the same x-axis and y-axis coordinates, 4 and 1.25, respectively. In rising to the right, the two plots diverge, but not by much. The plot for the FC-S-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-rises most steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively. The plot for the PC-A model-with an 8-inch-radius top bevel and 6-inch corner fillets-rises the least, ending at x-axis and y-axis coordinates of approximately 6 and 2, respectively. One inch equals 2.54 centimeters.

Figure 96. Graph. Inlet control, FC-S-0 and PC-A, 12-inch corner fillets.

The x-axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-FC-S-0 and PC-A-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.35, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. For the submerged condition, the two plots, which are in the upper right portion of the graph, begin at approximately the same x-axis and y-axis coordinates, 4.1 and 1.25, respectively. In rising to the right, the two plots diverge, but not by much. The plot for the FC-S-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and 12-inch corner fillets-rises most steeply, ending at x-axis and y-axis coordinates of approximately 6.2 and 2.25, respectively. The plot for the PC-A model-with an 8-inch-radius top bevel and 12-inch corner fillets-rises the least, ending at x-axis and y-axis coordinates of approximately 6.2 and 2.05, respectively. One inch equals 2.54 centimeters.

Figure 97. Graph. Inlet control, FC-S-30, FC-S-0, and PC-A.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three models-FC-S-30, FC-S-0, and PC-A-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots of FC-S-0 and PC-A, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.35, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The unsubmerged condition plot of FC-S-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.25, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.8, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-S-0 and PC-A begin at approximately the same x-axis and y-axis coordinates, 4 and 1.25, respectively. In rising to the right, the two plots diverge, but not by much. The plot for the FC-S-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-rises most steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively. The plot for the PC-A model-with an 8-inch-radius top bevel and 12-inch corner fillets-rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6.1 and 2.1, respectively. The submerged condition plot for the FC-S-30 model-with 30-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-is a bit lower than the plots for the FC-S-0 and PC-A models. The x-axis and y-axis coordinates of the leftmost point are approximately 4 and 1.2, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 6 and 1.9, respectively. One inch equals 2.54 centimeters

Figure 98. Graph. Inlet control, PC-A, 6- and 12-inch corner fillets.

The x-axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio H W divided by D and ranges from 0 to 2.5. Two PC-A models are plotted, one model with 6-inch corner fillets and one model with 12-inch corner fillets. Each model has an 8-inch-radius top bevel and a 2-to-1 span-to-rise ratio. One inch equals 2.54 centimeters. Each model is plotted for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. For the submerged condition, the two plots, which are in the upper right portion of the graph, begin at approximately the same x-axis and y-axis coordinates, 4 and 1.35, respectively. In rising to the right, the two plots diverge, but only barely. The plot for the model with 6-inch fillets rises most steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2, respectively. The plot for the model with 12-inch fillets rises a slightly lesser amount, ending at x-axis and y-axis coordinates of approximately 6.2 and 2, respectively.

Figure 99. Graph. Inlet control, field cast hybrid inlet with 4-inch-radius bevel on wingwalls.

The x-axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-FC-S-0 and FC-hybrid-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Both models have a single barrel, a field cast top bevel, and 0-inch corner fillets. For the unsubmerged condition, the plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1.1, respectively. For the submerged condition, the two plots, which are in the upper right portion of the graph, are again virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.3, respectively. The x-axis and y-axis coordinates of the rightmost points are approximately 6 and 2.25, respectively. The FC-S-0 model has a field cast top plate and field cast wingwalls. The FC-hybrid model has a field cast top plate and precast wingwalls. One inch equals 2.54 centimeters.

Figure 100. Graph. Inlet control, precast hybrid inlet with no bevel on wingwalls.

The x-axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-PC-A and PC-hybrid-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Both models have a single barrel, an 8-inch-radius top bevel, and 0-inch corner fillets. For the unsubmerged condition, the plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1.1, respectively. For the submerged condition, the two plots, which are in the upper right portion of the graph, begin at approximately the same x-axis and y-axis coordinates, 4 and 1.3, respectively. In rising to the right, the two plots diverge, but not by much. The plot for the PC-A model-with a precast top plate and precast wingwalls-rises most steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.1, respectively. The plot for the PC-hybrid model-with a precast top plate and field cast wingwalls-rises the least, ending at x-axis and y-axis coordinates of approximately 6 and 2, respectively. One inch equals 2.54 centimeters.

Figure 101. Graph. Inlet control, FC-S-0, FC-D-0, FC-T-0, and FC-Q-0.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Four models-FC-S-0 single, FC-D-0 double, FC-T-0 triple, and FC-Q-0 quad-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. All of the models have 6-inch corner fillets and 0-degree-flared wingwalls. One inch equals 2.54 centimeters. For the unsubmerged condition, the four plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.35, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-D-0 double, FC-T-0 triple, and FC-Q-0 quad are virtually identical. The x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.3, respectively. The plots rise to the right, and the x-axis and y-axis coordinates of the rightmost points are approximately 6 and 2.1, respectively. The plot of FC-S-0 single for the submerged condition is slightly steeper than the other three plots. The x-axis and y-axis coordinates of its leftmost point are approximately 4 and 1.25, respectively. Its rightmost point has x-axis and y-axis coordinates of approximately 6 and 2.2, respectively.

Figure 102. Graph. Inlet control, FC-S-0, FC-D-0-E, FC-T-0-E, and FC-Q-0-E.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Four models-FC-S-0 single, FC-D-0-E double, FC-T-0-E triple, and FC-Q-0-E quad-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. All of the models have 6-inch corner fillets and 0-degree-flared wingwalls. One inch equals 2.54 centimeters. The last three models have extended center walls. For the unsubmerged condition, the four plots, which are in the lower left corner of the graph, are very close. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. For the submerged condition, which is in the upper right portion of the graph, the plot of FC-S-0 single is the steepest of the four plots, all of which rise to the right. The x-axis and y-axis coordinates of the leftmost point of FC-S-0 single are approximately 4 and 1.25, respectively. The x-axis and y-axis coordinates of the rightmost point are approximately 6 and 2.2, respectively. The plots for FC-T-0-E triple and FC-Q-0-E quad for the submerged condition are very close. The x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.3, respectively. The x-axis and y-axis coordinates of the rightmost points are approximately 6 and 2.2, respectively. The plot of FC-D-0-E double for the submerged condition is slightly flatter than the plots for FC-T-0-E triple and FC-Q-0-E quad. The x-axis and y-axis coordinates of the leftmost point for FC-D-0-E double are approximately 4 and 1.3, respectively. Its rightmost point has x-axis and y-axis coordinates of approximately 6 and 2.1, respectively.

Figure 103. Graph. Inlet control, FC-S-30, FC-D-30, FC-T-30, and FC-Q-30.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Four models-FC-S-30 single, FC-D-30 double, FC-T-30 triple, and FC-Q-30 quad-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. All of the models have 6-inch corner fillets and 30-degree-flared wingwalls. One inch equals 2.54 centimeters. For the unsubmerged condition, the four plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 0.9, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-D-30 double, FC-T-30 triple, and FC-Q-30 quad are very close. The x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.2, respectively. The plots rise to the right, and the x-axis and y-axis coordinates of the rightmost points are approximately 6 and 2, respectively. The plot of FC-S-0 single for the submerged condition is slightly steeper than the other three plots. The x-axis and y-axis coordinates of its leftmost point are approximately 4 and 1.15, respectively. Its rightmost point has x-axis and y-axis coordinates of approximately 6 and 2, respectively.

Figure 104. Graph. Inlet control, FC-S-30, FC-D-30-E, FC-T-30-E, and FC-Q-30-E.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Four models-FC-S-30 single, FC-D-30-E double, FC-T-30-E triple, and FC-Q-30-E quad-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. All of the models have 6-inch corner fillets and 30-degree-flared wingwalls. One inch equals 2.54 centimeters. The last three models have extended center walls. For the unsubmerged condition, the four plots, which are in the lower left corner of the graph, are very similar. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 0.9, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-D-30-E double, FC-T-30-E triple, and FC-Q-30-E quad are very close. The x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.2, respectively. The plots rise to the right, and the x-axis and y-axis coordinates of the rightmost points are approximately 6 and 2, respectively. The plot of FC-S-0 single for the submerged condition is slightly steeper than the other three plots. The x-axis and y-axis coordinates of its leftmost point are approximately 4 and 1.15, respectively. Its rightmost point has x-axis and y-axis coordinates of approximately 6 and 2, respectively.

Figure 105. Graph. Inlet control, FC-S-0 and FC-S-30.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-FC-S-0 with 0-degree-flared wingwalls and FC-S-30 with 30-degree-flared wingwalls-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Both models are single barrel with 6-inch corner fillets. One inch equals 2.54 centimeters. For the unsubmerged condition, the two plots, which are in the lower left corner of the graph, rise from left to right. For the FC-S-0 model, the x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.35, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. For the FC-S-30 model, the x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.25, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 0.85, respectively. The plots for the submerged condition are in the upper right portion of the graph and also rise from left to right. For the FC-S-0 model, the x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.25, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 6 and 2.2, respectively. For the FC-S-30 model, the x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.15, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 6 and 2, respectively.

Figure 106. Graph. Inlet control, FC-D-0 and FC-D-30.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-FC-D-0 with 0-degree-flared wingwalls and FC-D-30 with 30-degree-flared wingwalls-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Both models are double barrel with 6-inch corner fillets. One inch equals 2.54 centimeters. For the unsubmerged condition, the two plots, which are in the lower left corner of the graph, rise from left to right. For the FC-D-0 model, the x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.35, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. For the FC-D-30 model, the x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.25, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 0.85, respectively. The plots for the submerged condition are in the upper right portion of the graph and also rise from left to right. For the FC-D-0 model, the x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.3, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 6 and 2.1, respectively. For the FC-D-30 model, the x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.25, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 6 and 2, respectively.

Figure 107. Graph. Inlet control, FC-T-0 and FC-T-30.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-FC-T-0 with 0-degree-flared wingwalls and FC-T-30 with 30-degree-flared wingwalls-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Both models are triple barrel with 6-inch corner fillets. One inch equals 2.54 centimeters. For the unsubmerged condition, the two plots, which are in the lower left corner of the graph, rise from left to right. For the FC-T-0 model, the x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. For the FC-T-30 model, the x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.3, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 0.9, respectively. The plots for the submerged condition are in the upper right portion of the graph and also rise from left to right. For the FC-T-0 model, the x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.3, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 6 and 2.1, respectively. For the FC-T-30 model, the x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.25, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 6 and 2, respectively.

Figure 108. Graph. Inlet control, FC-Q-0 and FC-Q-30.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-FC-Q-0 with 0-degree-flared wingwalls and FC-Q-30 with 30-degree-flared wingwalls-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Both models are quad barrel with 6-inch corner fillets. One inch equals 2.54 centimeters. For the unsubmerged condition, the two plots, which are in the lower left corner of the graph, rise from left to right. For the FC-Q-0 model, the x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. For the FC-Q-30 model, the x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.35, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 0.9, respectively. The plots for the submerged condition are in the upper right portion of the graph and also rise from left to right. For the FC-Q-0 model, the x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.3, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 6 and 2.1, respectively. For the FC-T-30 model, the x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.25, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 6 and 2, respectively.

Figure 109. Graph. Inlet control, FC-D-0 and FC-D-0-E.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-the nonextended center wall FC-D-0 and the extended center wall FC-D-0-E-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Both models are double barrel with 6-inch corner fillets and 0-degree-flared wingwalls. One inch equals 2.54 centimeters. For the unsubmerged condition, the two plots, which are in the lower left corner of the graph, rise from left to right and are virtually identical. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.35, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The plots for the submerged condition are in the upper right portion of the graph and also rise from left to right, and also are virtually identical. The x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.3, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 6 and 2.15, respectively.

Figure 110. Graph. Inlet control, FC-T-0 and FC-T-0-E.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-the nonextended center wall FC-T-0 and the extended center wall FC-T-0-E-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Both models are triple barrel with 6-inch corner fillets and 0-degree-flared wingwalls. One inch equals 2.54 centimeters. For the unsubmerged condition, the two plots, which are in the lower left corner of the graph, rise from left to right and are very similar. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The plots for the submerged condition are in the upper right portion of the graph and also rise from left to right. The plots begin at approximately the same x-axis and y-axis coordinates, 4 and 1.3, respectively. In rising to the right, the plots diverge slightly. The x axis and y-axis coordinates of the rightmost point of FC-T-0-E are approximately 6 and 2.2, respectively. The x-axis and y-axis coordinates of the rightmost point of FC-T-0 are approximately 6 and 2.15, respectively.

Figure 111. Graph. Inlet control, FC-Q-0 and FC-Q-0-E.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-the nonextended center wall FC-Q-0 and the extended center wall FC-Q-0-E-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Both models are quad barrel with 6-inch corner fillets and 0-degree-flared wingwalls. One inch equals 2.54 centimeters. For the unsubmerged condition, the two plots, which are in the lower left corner of the graph, rise from left to right and are very similar. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The plots for the submerged condition are in the upper right portion of the graph and also rise from left to right. The plots begin at approximately the same x-axis and y-axis coordinates, 4 and 1.3, respectively. In rising to the right, the plots diverge slightly. The x axis and y-axis coordinates of the rightmost point of FC-Q-0-E are approximately 6 and 2.2, respectively. The x-axis and y-axis coordinates of the rightmost point of FC-Q-0 are approximately 6 and 2.1, respectively.

Figure 112. Graph. Inlet control, FC-D-30 and FC-D-30-E.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-the nonextended center wall FC-D-30 and the extended center wall FC-D-30-E-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Both models are double barrel with 6-inch corner fillets and 30-degree-flared wingwalls. One inch equals 2.54 centimeters. For the unsubmerged condition, the two plots, which are in the lower left corner of the graph, rise from left to right and are virtually identical. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.25, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 0.85, respectively. The plots for the submerged condition are in the upper right portion of the graph and also rise from left to right, and also are virtually identical. The x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.2, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 6 and 2, respectively.

Figure 113. Graph. Inlet control, FC-T-30 and FC-T-30-E.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-the nonextended center wall FC-T-30 and the extended center wall FC-T-30-E-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Both models are triple barrel with 6-inch corner fillets and 30-degree-flared wingwalls. One inch equals 2.54 centimeters. For the unsubmerged condition, the two plots, which are in the lower left corner of the graph, rise from left to right and are very close. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.3, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 0.9, respectively. The plots for the submerged condition are in the upper right portion of the graph and also rise from left to right, and also are very close. The x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.25, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 6 and 2, respectively.

Figure 114. Graph. Inlet control, FC-Q-30 and FC-Q-30-E.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-the nonextended center wall FC-Q-30 and the extended center wall FC-Q-30-E-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Both models are double barrel with 6-inch corner fillets and 30-degree-flared wingwalls. One inch equals 2.54 centimeters. For the unsubmerged condition, the two plots, which are in the lower left corner of the graph, rise from left to right and are very close. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.3, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 0.9, respectively. The plots for the submerged condition are in the upper right portion of the graph and also rise from left to right, and also are very close. The x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.25, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 6 and 2, respectively.

Figure 115. Graph. Inlet control, PC-A, PC-B, PC-C, and PC-D.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Four models-PC-A single, PC-B double, PC-C triple, and PC-D quad-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Each of the models has an 8-inch-radius top bevel and 12-inch corner fillets. One inch equals 2.54 centimeters. For the unsubmerged condition, the four plots, which are in the lower left corner of the graph, are very close. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The plots for the submerged condition, which are in the upper right portion of the graph, also rise from left to right. The plots of PC-B double and PC-D quad are virtually identical. The x-axis and y-axis coordinates of the leftmost points are approximately 4.1 and 1.3, respectively; the x-axis and y-axis coordinates of the rightmost points are approximately 6.2 and 1.8, respectively. The plot of PC-C triple for the submerged condition is slightly steeper than the plots of PC-B double and PC-D quad. The x-axis and y-axis coordinates of its leftmost point are approximately 4.1 and 1.35, respectively; its rightmost point has x-axis and y-axis coordinates of approximately 6.2 and 1.95, respectively. The plot of PC-A single is the steepest of the submerged condition plots. The x-axis and y-axis coordinates of its leftmost point are approximately 4.1 and 1.25, respectively; its rightmost point has x-axis and y-axis coordinates of approximately 6.2 and 2.1, respectively.

Figure 116. Graph. Inlet control, PC-A, PC-B-E, PC-C-E, and PC-D-E.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Four models-PC-A single, PC-B-E double, PC-C-E triple, and PC-D-E quad-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Each of the models has 12-inch corner fillets. All of the models except PC-A have extended center walls. One inch equals 2.54 centimeters. For the unsubmerged condition, the four plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The plots for the submerged condition, which are in the upper right portion of the graph, also rise from left to right. The plots of PC-B-E and PC-D-E are virtually identical. The x-axis and y-axis coordinates of the leftmost points are approximately 4.1 and 1.35, respectively; the x-axis and y-axis coordinates of the rightmost points are approximately 6.2 and 2, respectively. The plot of PC-C-E for the submerged condition is not as steep as the plots of PC-B-E and PC-D-E. The x-axis and y-axis coordinates of its leftmost point are approximately 4.1 and 1.35, respectively; its rightmost point has x-axis and y-axis coordinates of approximately 6.2 and 1.9, respectively. The plot of PC-A is the steepest of the submerged condition plots. The x-axis and y-axis coordinates of its leftmost point are approximately 4.1 and 1.25, respectively; its rightmost point has x-axis and y-axis coordinates of approximately 6.2 and 2.1, respectively.

Figure 117. Graph. Inlet control, PC-B and PC-B-E.

The x-axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-the nonextended center wall PC-B and the extended center wall PC-B-E-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Each model has a double barrel, an 8-inch-radius top bevel, and 12-inch corner fillets. One inch equals 2.54 centimeters. For the unsubmerged condition, the plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.6 and 1, respectively. For the submerged condition, the two plots, which are in the upper right portion of the graph, are again virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 4.1 and 1.3, respectively. The x-axis and y-axis coordinates of the rightmost point of PC-B-E, and of both plotted lines, are approximately 6.2 and 2, respectively. The rightmost point of PC-B, with x-axis and y-axis coordinates of approximately 6.2 and 1.8, was assumed to be an outlier and was disregarded in computing the plot for PC-B.

Figure 118. Graph. Inlet control, PC-C and PC-C-E.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Two models-the nonextended center wall PC-C and the extended center wall PC-C-E-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. Both models are triple barrel with 12-inch corner fillets and 8-inch-radius top bevels. One inch equals 2.54 centimeters. For the unsubmerged condition, the two plots, which are in the lower left corner of the graph, rise from left to right and are virtually identical. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 2.6 and 1, respectively. The plots for the submerged condition are in the upper right portion of the graph and also rise from left to right, and also are virtually identical. The x-axis and y-axis coordinates of the leftmost points are approximately 4.1 and 1.3, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 6.2 and 1.9, respectively.

Figure 119. Graph. Inlet control, FC-S-30, FC-S-0, and PC-A.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three models-FC-S-30, FC-S-0, and PC-A-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots of FC-S-0 and PC-A, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The unsubmerged condition plot of FC-S-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.8, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-S-0 and PC-A begin at approximately the same x-axis and y-axis coordinates, 4 and 1.25, respectively. In rising to the right, the two plots diverge. The plot for the FC-S-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-rises more steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively. The plot for the PC-A model-with an 8-inch-radius top bevel and 12-inch corner fillets-rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6.1 and 2.1, respectively. The submerged condition plot for the FC-S-30 model-with 30-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-roughly parallels but is lower than the plot for the FC-S-0 model. The x-axis and y-axis coordinates of the leftmost point are approximately 4 and 1.2, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 6 and 1.9, respectively. One inch equals 2.54 centimeters.

Figure 120. Graph. Inlet control, FC-D-30, FC-D-0, and PC-B.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three models-FC-D-30, FC-D-0, and PC-B-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots of FC-D-0 and PC-B, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.35, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The unsubmerged condition plot of FC-D-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.85, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-D-0 and PC-B begin at approximately the same x-axis and y-axis coordinates, 4 and 1.3, respectively. In rising to the right, the two plots diverge. The plot for the FC-D-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-rises more steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.1, respectively. The plot for the PC-B model-with an 8-inch-radius top bevel and 12-inch corner fillets-rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6.1 and 1.7, respectively. The submerged condition plot for the FC-D-30 model-with 30-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-roughly parallels but is lower than the plot for the FC-D-0 model. The x-axis and y-axis coordinates of the leftmost point are approximately 4 and 1.2, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 6 and 1.9, respectively. One inch equals 2.54 centimeters.

Figure 121. Graph. Inlet control, FC-T-30, FC-T-0, and PC-C.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three models-FC-T-30, FC-T-0, and PC-C-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots of FC-T-0 and PC-C, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The unsubmerged condition plot of FC-T-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.85, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-T-0 and PC-C begin at approximately the same x-axis and y-axis coordinates, 4 and 1.3, respectively. In rising to the right, the two plots diverge. The plot for the FC-T-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-rises more steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.1, respectively. The plot for the PC-C model-with an 8-inch-radius top bevel and 12-inch corner fillets-rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6.1 and 1.9, respectively. The submerged condition plot for the FC-T-30 model-with 30-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-roughly parallels but is lower than the plot for the FC-T-0 model. The x-axis and y-axis coordinates of the leftmost point are approximately 4 and 1.2, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 6 and 2, respectively. One inch equals 2.54 centimeters.

Figure 122. Graph. Inlet control, FC-Q-30, FC-Q-0, and PC-D.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three models-FC-Q-30, FC-Q-0, and PC-D-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots of FC-Q-0 and PC-D, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The unsubmerged condition plot of FC-Q-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.85, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-Q-0 and PC-D begin at approximately the same x-axis and y-axis coordinates, 4 and 1.3, respectively. In rising to the right, the two plots diverge. The plot for the FC-Q-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-rises more steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.1, respectively. The plot for the PC-D model-with an 8-inch-radius top bevel and 12-inch corner fillets-rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6.1 and 1.8, respectively. The submerged condition plot for the FC-Q-30 model-with 30-degree wingwalls, a 4-inch-straight top bevel, and 6-inch corner fillets-roughly parallels but is lower than the plot for the FC-Q-0 model. The x-axis and y-axis coordinates of the leftmost point are approximately 4 and 1.2, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 6 and 2, respectively. One inch equals 2.54 centimeters.

Figure 123. Graph. Inlet control, FC-S-0, various span-to-rise ratios.

The x-axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Four FC-S-0 models are plotted. The models differ in their span-to-rise ratios: 1-to-1, 2-to-1, 3-to-1, and 4-to-1. Each model has no corner fillets and 0-degree-flared wingwalls. The plots are for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots, which are in the lower left corner of the graph, are very close but do show a small loss in performance-evidenced by slightly higher plots-as the span-to-rise ratio increases. The plots rise from left to right. The x-axis coordinates of the leftmost points are approximately 0.5. The y-axis coordinates of the leftmost points range from approximately 0.35 to 0.4, with the leftmost point of the 1-to-1 span-to-rise plot being the lowest. The x axis coordinates of the rightmost points are approximately 2.5. The y-axis coordinates of the rightmost points range from approximately 1 to 1.05, with the rightmost point of the 1-to-1 span-to-rise plot being the lowest. For the submerged condition, the four plots, which are in the upper right portion of the graph, are very close. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.35, respectively, except that the y-axis coordinate of the leftmost point of the 1-to-1 span-to-rise plot is approximately 1.25. The x-axis and y-axis coordinates of the rightmost points of all four plots are approximately 6 and 2.2, respectively.

Figure 124. Graph. Inlet control, FC-S-30, various span-to-rise ratios.

The x-axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Four FC-S-30 models are plotted. The models differ in their span-to-rise ratios: 1-to-1, 2-to-1, 3-to-1, and 4-to-1. Each model has no corner fillets and 30-degree-flared wingwalls. The plots are for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 0.9, respectively. For the submerged condition, the plots show a decrease in performance-evidenced by higher plots-as the span-to-rise ratio increases. The lowest plot is for the 1-to-1 span-to-rise ratio. The x-axis and y-axis coordinates of its leftmost point are 4 and 1.1, respectively. The x-axis and y-axis coordinates of its rightmost point are 6 and 1.9, respectively. The highest plot is for the 4-to-1 span-to-rise ratio. The x-axis and y-axis coordinates of its leftmost point are 4 and 1.25, respectively. The x-axis and y-axis coordinates of its rightmost point are 6 and 2.05, respectively.

Figure 125. Graph. Inlet control, PC-A, various span-to-rise ratios.

The x-axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Four PC-A models are plotted. The models differ in their span-to-rise ratios: 1-to-1, 2-to-1, 3-to-1, and 4-to-1. Each model has no corner fillets and an 8-inch-radius top bevel. One inch equals 2.54 centimeters. The plots are for two conditions: inlet control unsubmerged and inlet control submerged. For the unsubmerged condition, the plots, which are in the lower left corner of the graph, are very close but do show a small loss in performance-evidenced by slightly higher plots-as the span-to-rise ratio increases. The plots rise from left to right. The x-axis coordinates of the leftmost points are approximately 0.5. The y-axis coordinates of the leftmost points range from approximately 0.35 to 0.4, with the leftmost point of the 1-to-1 span-to-rise plot being the lowest. The x axis coordinates of the rightmost points are approximately 2.5. The y-axis coordinates of the rightmost points range from approximately 1 to 1.05, with the rightmost point of the 1-to-1 span-to-rise plot being the lowest. For the submerged condition, the four plots, which are in the upper right portion of the graph, are very close. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 4 and 1.35, respectively, except that the y-axis coordinate of the leftmost point of the 1-to-1 span-to-rise plot is approximately 1.25. The x-axis and y-axis coordinates of the rightmost points of all four plots are approximately 6 and 2, respectively.

Figure 126. Graph. Inlet control, FC-S-30, FC-S-0, and PC-A, 1-to-1 span-to-rise ratio.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three models-FC-S-0, FC-S-30, and PC-A-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. The span-to-rise ratio of each model is 1-to-1. For the unsubmerged condition, the plots of FC-S-0 and PC-A, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The unsubmerged condition plot of FC-S-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.25, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.8, respectively. For the submerged condition, which is in the upper right portion of the graph, each model has a unique plot, all of which rise to the right. The plot of the FC-S-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and no corner fillets-begins at x-axis and y-axis coordinates of approximately 4 and 1.25, respectively. The plot ends at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively . The submerged condition plot for the PC-A model-with an 8-inch-radius top bevel and no corner fillets-begins at x-axis and y-axis coordinates of approximately 4 and 1.3, respectively. The plot ends at x-axis and y-axis coordinates of approximately 6 and 2, respectively. The submerged condition plot for the FC-S-30 model-with 30-degree-flared wingwalls, a 4-inch-straight top bevel, and no corner fillets-begins at x-axis and y-axis coordinates of approximately 4 and 1.1, respectively. The plot ends at x-axis and y-axis coordinates of approximately 6 and 1.9, respectively. One inch equals 2.54 centimeters.

Figure 127. Graph. Inlet control, FC-S-30, FC-S-0, and PC-A, 2-to-1 span-to-rise ratio.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three models-FC-S-0, FC-S-30, and PC-A-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. The span-to-rise ratio of each model is 2-to-1. For the unsubmerged condition, the plots of FC-S-0 and PC-A, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The unsubmerged condition plot of FC-S-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.25, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.8, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-S-0 and PC-A begin at approximately the same x-axis and y-axis coordinates, 4 and 1.3, respectively. In rising to the right, the two plots diverge. The plot for the FC-S-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and no corner fillets-rises more steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively. The plot for the PC-A model-with an 8-inch-radius top bevel and no corner fillets-rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6 and 2, respectively. The submerged condition plot for the FC-S-30 model-with 30-degree-flared wingwalls, a 4-inch-straight top bevel, and no corner fillets-begins at x-axis and y-axis coordinates of approximately 4 and 1.2, respectively. The plot ends at x-axis and y-axis coordinates of approximately 6 and 2, respectively. One inch equals 2.54 centimeters.

Figure 128. Graph. Inlet control, FC-S-30, FC-S-0, and PC-A, 3-to-1 span-to-rise ratio.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three models-FC-S-0, FC-S-30, and PC-A-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. The span-to-rise ratio of each model is 3-to-1. For the unsubmerged condition, the plots of FC-S-0 and PC-A, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.4, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1, respectively. The unsubmerged condition plot of FC-S-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.25, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.8, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-S-0 and PC-A begin at approximately the same x-axis and y-axis coordinates, 4 and 1.3, respectively. In rising to the right, the two plots diverge. The plot for the FC-S-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and no corner fillets-rises more steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively. The plot for the PC-A model-with an 8-inch-radius top bevel and no corner fillets-rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6 and 2, respectively. The submerged condition plot for the FC-S-30 model-with 30-degree-flared wingwalls, a 4-inch-straight top bevel, and no corner fillets-begins at x-axis and y-axis coordinates of approximately 4 and 1.2, respectively. The plot ends at x-axis and y-axis coordinates of approximately 6 and 2.05, respectively. One inch equals 2.54 centimeters.

Figure 129. Graph. Inlet control, FC-S-30, FC-S-0, and PC-A, 4-to-1 span-to-rise ratio.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. Three models-FC-S-0, FC-S-30, and PC-A-are plotted, each for two conditions: inlet control unsubmerged and inlet control submerged. The span-to-rise ratio of each model is 4-to-1. For the unsubmerged condition, the plots of FC-S-0 and PC-A, which are in the lower left corner of the graph, are virtually identical. They rise from left to right. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.45, respectively. The x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1.05, respectively. The unsubmerged condition plot of FC-S-30 is also in the lower left corner of the graph but a bit lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.3, respectively. The x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.85, respectively. For the submerged condition, which is in the upper right portion of the graph, the plots of FC-S-0 and PC-A begin at approximately the same x-axis and y-axis coordinates, 4 and 1.35, respectively. In rising to the right, the two plots diverge. The plot for the FC-S-0 model-with 0-degree-flared wingwalls, a 4-inch-straight top bevel, and no corner fillets-rises more steeply, ending at x-axis and y-axis coordinates of approximately 6 and 2.2, respectively. The plot for the PC-A model-with an 8-inch-radius top bevel and no corner fillets-rises a lesser amount, ending at x-axis and y-axis coordinates of approximately 6 and 2, respectively. The submerged condition plot for the FC-S-30 model-with 30-degree-flared wingwalls, a 4-inch-straight top bevel, and no corner fillets-begins at x-axis and y-axis coordinates of approximately 4 and 1.25, respectively. The plot ends at x-axis and y-axis coordinates of approximately 6 and 2.05, respectively. One inch equals 2.54 centimeters.

Figure 130. Graph. Inlet control, FC-T-30 at various headwall skews.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. The FC-T-30 model at four headwall skews-0, 15, 30, and 45 degrees-is plotted, each plot being for two conditions: inlet control unsubmerged and inlet control submerged. The FC model is triple barrel with no corner fillets and nonextended center walls. For the unsubmerged condition, the plots are in the lower left corner of the graph and rise from left to right. Three of the plots, for skews of 15, 30, and 45 degrees, are very close. The x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.5, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 1.05, respectively. The plot for 0-degree skew is lower. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.3, respectively; the x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 0.9, respectively. The plots for the submerged condition, which are in the upper right portion of the graph, also rise from left to right. The leftmost points of the plots for skews of 15, 30, and 45 degrees have approximately the same x-axis and y-axis coordinates: 4 and 1.45, respectively. The rightmost point for the plot of the 15-degree skew has x-axis and y-axis coordinates of approximately 6 and 2, respectively. The rightmost point for the plot of the 30-degree skew has x-axis and y-axis coordinates of approximately 6 and 2.1, respectively. The rightmost point for the plot of the 45-degree skew has x-axis and y-axis coordinates of approximately 6 and 0.9, respectively. The submerged condition plot of the 0-degree skew is steeper than the other three plots. The x-axis and y-axis coordinates of its leftmost point are approximately 4 and 1.25, respectively; its rightmost point has x-axis and y-axis coordinates of approximately 6 and 2, respectively.

Figure 131. Graph. Inlet control, FC-S-30, 0- and 30-degree skews.

The x axis is the quotient of Q divided by the product of A times D to the 0.5 power and is in feet to the one-half power per second, ranging from 0 to 7. One foot to the one-half power per second equals 0.552 meters to the one-half power per second. The y-axis is the dimensionless ratio HW divided by D and ranges from 0 to 2.5. The FC-S-30 model with a 3-to-1 span-to-rise ratio is plotted for two headwall skews-0 and 30 degrees. Each plot is for two conditions: inlet control unsubmerged and inlet control submerged. The FC-S-30 model has no corner fillets and 30-degree-flared wingwalls. For the unsubmerged condition, the plots are in the lower left corner of the graph and rise from left to right. For the plot for 0-degree skew, the x-axis and y-axis coordinates of the leftmost points are approximately 0.5 and 0.3, respectively; the x axis and y-axis coordinates of the rightmost points are approximately 2.5 and 0.85, respectively. The unsubmerged condition plot for 30-degree skew is higher. The x-axis and y-axis coordinates of the leftmost point are approximately 0.5 and 0.5, respectively; the x axis and y-axis coordinates of the rightmost point are approximately 2.5 and 1, respectively. The plots for the submerged condition, which are in the upper right portion of the graph, also rise from left to right. The leftmost point of the plot for 0-degree skew has x-axis and y-axis coordinates of approximately 4 and 1.2, respectively; the rightmost point has x-axis and y-axis coordinates of approximately 6 and 2, respectively. The leftmost point of the plot for 30-degree skew has x-axis and y-axis coordinates of approximately 4 and 1.4, respectively; the rightmost point has x-axis and y-axis coordinates of approximately 6 and 2, respectively.

Figure 132. Equation. Fifth-order polynomial.

The quotient HW subscript i divided by D equals the sum of six terms. The first term is a. The second term is the product of b times the quotient of the product of K subscript u times Q divided by the product of A times D to the power of 0.5. The third term is the product of c times the quotient to the power of 2 of the product of K subscript u times Q divided by the product of A times D to the power of 0.5. The fourth term is the product of d times the quotient to the power of 3 of the product of K subscript u times Q divided by the product of A times D to the power of 0.5. The fifth term is the product of e times the quotient to the power of 4 of the product of K subscript u times Q divided by the product of A times D to the power of 0.5. The sixth term is the product of f times the quotient to the power of 5 of the product of K subscript u times Q divided by the product of A times D to the power of 0.5

Figure 133. Graph. Discharge, tailwater variation.

The x-axis is tailwater elevation in feet and ranges from 82.5 to 86.5. The y-axis is discharge in cubic feet per second and ranges from 0 to 1800. An exponential plot rises from left to right. The x-axis and y-axis coordinates of the leftmost point are approximately 82.75 and 50, respectively. The x-axis and y-axis coordinates of the rightmost point are approximately 86 and 1600, respectively. For the Q subscript 25, or 25-year, peak flow of 773 cubic feet per second, the tailwater elevation is 84.78 feet. For the Q subscript 100, or 100-year, peak flow of 1602 cubic feet per second, the tailwater elevation is 86 feet. One foot equals 0.305 meters. One cubic foot per second equals 0.028 cubic meters per second.

Figure 134. Graph. Downstream cross section.

The x-axis is the X distance in feet and ranges from 0 to 500. The y-axis is ground elevation in feet and ranges from 78 to 86. The water surface for the Q subscript 25, or 25-year, peak flow is indicated by a horizontal line at approximately 84.7 feet. The stream bed is indicated by a plotted line. The leftmost point has x-axis and y-axis coordinates of approximately 70 and 86, respectively. The plot descends gradually to the right to x-axis and y-axis coordinates of approximately 280 and 82, respectively. This point is labeled Edge of channel. The plot then descends sharply to x-axis and y-axis coordinates of approximately 300 and 78.5, respectively. From there, the plot first rises sharply to x-axis and y-axis coordinates of approximately 320 and 82, respectively, then levels off before reaching x-axis and y-axis coordinates of approximately 480 and 83, respectively. After a final sharp rise, the plot reaches its rightmost point, which has x-axis and y-axis coordinates of approximately 500 and 86, respectively. One foot equals 0.305 meters.

Figure 135. Graph. Cross section area versus tailwater elevation.

The x-axis is tailwater elevation in feet and ranges from 82.5 to 86.5. The y-axis is flow area in square feet and ranges from 0 to 1400. An almost linear plot rises from left to right. The x-axis and y-axis coordinates of the leftmost point are approximately 82.75 and 150, respectively. The x-axis and y-axis coordinates of the rightmost point are approximately 86 and 1300, respectively. The equation for the flow area, A, is superimposed on the graph. A equals the sum of three terms. The first term is the product of 26.107 times the square of TW subscript elev. The second term is the negative product of 4044.9 times TW subscript elev. The third term is 156088. For the Q subscript 25, or 25-year, peak flow, A, which is also the y-axis coordinate, is 810.88 square feet. The corresponding tailwater elevation, which is the x-axis coordinate, is 84.78 feet. For the Q subscript 100, or 100-year, peak flow, A is 1310.80 square feet. The corresponding tailwater elevation is 86 feet. One foot equals 0.305 meters. One square foot equals 0.093 square meters.

Figure 136. Equation. Downstream flow area for tailwater elevation.

A equals the sum of three terms. The first term is the product of 26.107 times the square of TW subscript elev. The second term is the negative product of 4044.9 times TW subscript elev. The third term is 156088.

Figure 137. Equation. Flow area under headwater elevation.

A equals the sum of three terms. The first term is the product of 26.107 times the square of HW subscript elev. The second term is the negative product of 4045.777 times HW subscript elev. The third term is 156155.95.

Figure 138. Equation. Downstream channel velocity for Q subscript 25.

V subscript TW equals the quotient of Q divided by A, which substituting numbers is 773 divided by 810.88, which is 0.95 feet per second, or 0.29 meters per second. One foot equals 0.305 meters.

Figure 139. Equation. Downstream channel velocity for Q subscript 100.

V subscript TW equals the quotient of Q divided by A, which substituting numbers is 1602 divided by 1310.80, which is 1.22 feet per second, or 0.37 meters per second. One foot equals 0.305 meters.

Figure 140. Equation. Critical depth, below top corner fillets.

The left side of the equation is lowercase d subscript c. The right side of the equation is a quotient. The numerator of the quotient is the sum of two terms. The first term is the quotient to the one-third power of the product of Q squared times B divided by g. The second term is the product of NB times lowercase a squared. The denominator of the quotient is B.

Figure 141. Equation. Critical depth, partially submerged top corner fillets.

The left side of the equation is lowercase d subscript c. The right side of the equation is a quotient. The numerator of the quotient is the sum of two terms. The first term is the quotient to the one-third power of the product of Q squared times the difference of B minus the product of 2 times NB times lowercase a subscript t, all divided by g. The second term is the product of NB times the sum of lowercase a squared plus the square of lowercase a subscript t. The denominator of the quotient is B.

Figure 142. Equation. Normal culvert depth. Q equals the product of four terms.

The first term is the quotient of 1.49 divided by n. The second term is A. The third term is the two-thirds power of R subscript h. The fourth term is the one-half power of S subscript o.

Figure 143. Equations. Flow area and hydraulic radius, depth below top corner fillet.

The figure contains two equations. The first equation is A equals the product of NB times the difference of the product of lowercase d subscript n times span minus lowercase a squared. The second equation is R subscript h equals the quotient of A divided by the product of NB times the sum of span plus the product of 2 times lowercase d subscript n plus the negative of the product of 1.17 times lowercase a.

Figure 144. Equations. Flow area and hydraulic radius, top fillets partially submerged.

The figure contains two equations. The first equation is A equals the product of NB times the difference of the product of lowercase d subscript n times span minus the sum of lowercase a squared plus the square of lowercase a subscript t. The second equation is R subscript h equals the quotient of A divided by the product of NB times the sum of span plus the product of 2 times lowercase d subscript n plus the negative of the product of 1.17 times lowercase a plus the product of 0.848 times the square of lowercase a subscript t.

Figure 145. Equation. Initial depth.

The left side of the equation is the sum of lowercase d subscript o plus the quotient of the square of V subscript o divided by the product of 2 times g. The right side of the equation is the sum of four terms. The first term is TW Elevation. The second term is the quotient of the square of V subscript TW divided by the product of 2 times g. The third term is the negative of Invert Elevation. The fourth term is the product of K subscript o times the difference of the quotient of the square of V subscript o divided by the product of 2 times g, all minus the quotient of the square of V subscript TW divided by the product of 2 times g.

Figure 146. Equation. For K subscript o equals 1.0.

For K subscript o equals 1.0, lowercase d subscript o equals the difference of TW Elevation minus Invert Elevation.

Figure 147. Diagram. Definition sketch for exit loss.

The figure is a side view of a culvert exit, with the downstream or outlet side being to the right. The horizontal bottom of the culvert entrance is labeled Invert Elev. A dotted horizontal line above the culvert bottom is labeled T w Elev. The difference between T w Elev. and Invert Elev. is labeled lowercase d subscript o. A second dotted line descends diagonally from left to right on the top of the culvert. At the end of the top of the culvert, the line drops vertically to just above the line labeled T W Elev. and then extends horizontally to the right. The distance of the vertical drop is the product of K subscript o times the difference of the quotient of the square of V subscript o divided by the product of 2 times g, all minus the quotient of the square of V subscript TW divided by the product of 2 times g. The vertical distance between top dotted line before it drops at the culvert exit and the horizontal line labeled T W Elev. is the quotient of the square of V subscript o divided by the product of 2 times g.

Figure 148. Equation. Initial depth ignoring tailwater velocity head.

The term lowercase d subscript o equals the difference of TW elevation minus Invert Elevation at outlet. With a substitute of a number for the last term, the right side of the equation is TW Elevation minus 78.79.

Figure 149. Equations. For lowercase d less than parenthesis D minus lowercase a end parenthesis.

This figure contains four equations. The first equation is delta lowercase d equals a quotient. The numerator of the quotient is D minus lowercase a minus lowercase d subscript o. The denominator of the quotient is 1000. The equation is described as taking 1000 steps in the spreadsheet. The second equation is lowercase d subscript i equals the sum of lowercase d, with the subscript of i minus 1, plus delta lowercase d. The third equation is A subscript i equals the product of NB times the difference of the product of lowercase d subscript i times span minus lowercase a squared. The fourth equation is R subscript h-i equals the quotient of A subscript i divided by the product of NB times the sum of span plus the product of 2 times lowercase d subscript i plus the negative of the product of 1.17 times lowercase a.

Figure 150. Equations. For lowercase d less than D but greater than parenthesis D minus lowercase a end parenthesis.

This figure contains five equations. The first equation is delta lowercase d equals the quotient of lowercase a divided by 20. The equation is described as taking 19 steps in the spreadsheet. The second equation is lowercase d subscript i equals the sum of lowercase d, with the subscript of i minus 1, plus delta lowercase d. The third equation is lowercase a subscript t-i equals the difference of lowercase d subscript i minus the difference of D minus lowercase a. The fourth equation is A subscript i equals the product of NB times the difference of the product of lowercase d subscript i times span minus the sum of lowercase a squared plus the square of lowercase a subscript t-i. The fifth equation is R subscript h-i equals the quotient of A subscript i divided by the product of NB times the sum of span plus the product of 2 times lowercase d subscript i plus the negative of the product of 1.17 times lowercase a plus the product of 0.848 times lowercase a subscript ti.

Figure 151. Equations. For lowercase d equal to D parenthesis the last iteration end parenthesis.

This figure contains three equations. The first equation is lowercase d subscript i equals D. The second equation is A subscript i equals the product of NB times the difference of the product of D times span minus the product of 2 times lowercase a squared. The third equation is R subscript h-i equals the quotient of A subscript i divided by the product of NB times the sum of the product of 2 times span plus the product of 2 times D plus the negative of the product of 2.34 times lowercase a.

Figure 152. Equation. Friction slope.

S subscript F equals the square of the quotient of the product of n times Q divided by the product of 1.5 times A subscript m times the two-thirds power of R subscript h-m.

Figure 153. Equation. Step length. Delta L equals a quotient.

The numerator of the quotient is the difference between two terms. The first term is the sum of lowercase d subscript i plus the quotient of the square of V subscript i divided by the product of 2 times g. The second term is the sum of lowercase d, with the subscript of i plus 1, plus the quotient of the square of V, with the subscript of i plus 1, divided by the product of 2 times g.

Figure 154. Equation. E G L at upstream culvert end open parenthesis the entrance close parenthesis.

E G L subscript U-S equals the sum of three terms. The first term is D. The second term is the quotient of the square of V subscript FULL divided by the product of 2 times g. The third term is a product. The first term of the product is the quotient of 29 times n squared times L subscript FULL divided by the four-thirds power of R subscript HFULL. The second term of the product is the quotient of the square of V subscript FULL divided by the product of 2 times g.

Figure 155. Sketches. Entrance loss coefficients parenthesis K subscript e end parenthesis of culverts in example problem.

This figure contains three sketches, taken from figure 93 and labeled figure 155a through 155c, of the three basic inlets considered in the example problem. Each sketch is a perspective, or three-dimensional, drawing, with the near portion of the model on the left side and the distant portion on the right side. Here follows a description of each sketch. Figure 155a, which is from sketch 2 of figure 93, is of an FC-D-30 model inlet with a double barrel, 30-degree-flared wingwalls, and the top edge beveled at 45 degrees. The K subscript e coefficient is 0.32. Figure 155b, which is from sketch 8 of figure 93, is of an FC-D-0 model inlet with a double barrel, 0-degree-flared wingwalls, and the top edge beveled at 45 degrees. The K subscript e coefficient is 0.52. Figure 155c, which is from sketch 12 of figure 93, is of a PC-B model inlet with a double barrel, 0-degree-flared wingwalls with extended sides, the crown rounded at an 8-inch radius, and 12-inch corner fillets. The K subscript e coefficient is 0.54.

Figure 156. Equation. Entrance loss.

The term h subscript L-e equals the product of K subscript e times the quotient of the square of V subscript U-S divided by the product of 2 times g.

Figure 157. Equation. Headwater energy grade line.

HW subscript E G L equals the sum of E G L elevation subscript U-S plus h subscript L-e.

Figure 158. Equation. Headwater hydraulic grade line.

HW subscript E G L equals the sum of HW subscript H G L plus the quotient of the square of V subscript HW divided by the product of 2 times g. V subscript HW divided by the product of 2 times g equals the product of Q divided by A.

Figure 159. Diagram. FC-D-30 model, Q subscript 100 elevations.

The diagram has three parts. The top part is labeled Section A-A and is a head-on view of a two-barrel inlet. Each barrel is 9-feet wide by 8-feet high. The corners of the barrels have 6-inch fillets. The middle part of the diagram is labeled Plan View. It is an overhead view of the culvert. Two diagonal slash marks across the culvert indicate the depiction of the culvert's length has been abbreviated in the diagram. The bottom part of the diagram is labeled Profile View and is a side view of the culvert with a number of elevations and a dimension. The dimension is the length of the culvert from the top of the entrance to the top of the exit and is 84.0 feet. Two diagonal slash marks across the culvert indicate the depiction of the culvert's length has been abbreviated in the diagram. The entrance to the culvert is on the left, and the exit is on the right. On the left, the culvert entrance invert has an elevation of 78.81 feet; the HW E G L has an elevation of 89.25 feet; and the E G L has an elevation of 88.58 feet. The vertical drop in the E G L as it enters the culvert is given by the product of K subscript e times the quotient of the square of V subscript e divided by the product of 2 times g. At the culvert's center, the roadway elevation is 90.2 feet, and the critical depth within the culvert is 6.29 feet. On the right, the culvert outlet invert has an elevation of 78.79 feet; the E G L has an elevation of 88.38 feet; and the TW H G L has an elevation of 86 feet. The vertical drop from the E G L to the TW H G L at the exit is given by the product of K subscript o times the difference of the quotient of the square of V subscript o divided by the product of 2 times g, all minus the quotient of the square of V subscript TW divided by the product of 2 times g. One foot equals 0.305 meters.

Figure 160. Diagram. FC-D-0 model, Q subscript 100 elevations.

The diagram has three parts. The top part is labeled Section A-A and is a head-on view of a two-barrel inlet. Each barrel is 9-feet wide by 8-feet high. The corners of the barrels have 6-inch fillets. The middle part of the diagram is labeled Plan View. It is an overhead view of the culvert. Two diagonal slash marks across the culvert indicate the depiction of the culvert's length has been abbreviated in the diagram. The bottom part of the diagram is labeled Profile View and is a side view of the culvert with a number of elevations and a dimension. The dimension is the length of the culvert from the top of the entrance to the top of the exit and is 84.0 feet. Two diagonal slash marks across the culvert indicate the depiction of the culvert's length has been abbreviated in the diagram. The entrance to the culvert is on the left, and the exit is on the right. On the left, the culvert entrance invert has an elevation of 78.81 feet; the HW E G L has an elevation of 89.68 feet; and the E G L has an elevation of 88.58 feet. The vertical drop in the E G L as it enters the culvert is given by the product of K subscript e times the quotient of the square of V subscript e divided by the product of 2 times g. At the culvert's center, the roadway elevation is 90.2 feet, and the critical depth within the culvert is 6.29 feet. On the right, the culvert outlet invert has an elevation of 78.79 feet; the E G L has an elevation of 88.38 feet; and the TW H G L has an elevation of 86 feet. The vertical drop from the E G L to the T W H G L at the exit is given by the product of K subscript o times the difference of the quotient of the square of V subscript o divided by the product of 2 times g, all minus the quotient of the square of V subscript TW divided by the product of 2 times g. One foot equals 0.305 meters.

Figure 161. Diagram. PC-B model, 12-inch corner fillets, Q subscript 100 elevations.

The diagram has three parts. The top part is labeled Section A-A and is a head-on view of a two-barrel inlet. Each barrel is 9-feet wide by 8-feet high. The corners of the barrels have 12-inch fillets. The middle part of the diagram is labeled Plan View. It is an overhead view of the culvert. Two diagonal slash marks across the culvert indicate the depiction of the culvert's length has been abbreviated in the diagram. The bottom part of the diagram is labeled Profile View and is a side view of the culvert with a number of elevations and a dimension. The dimension is the length of the culvert from the top of the entrance to the top of the exit and is 84.0 feet. Two diagonal slash marks across the culvert indicate the depiction of the culvert's length has been abbreviated in the diagram. The entrance to the culvert is on the left, and the exit is on the right. On the left, the culvert entrance invert has an elevation of 78.81 feet; the H W E G L has an elevation of 89.84 feet; and the E G L has an elevation of 88.66 feet. The vertical drop in the E G L as it enters the culvert is given by the product of K subscript e times the quotient of the square of V subscript e divided by the product of 2 times g. At the culvert's center, the roadway elevation is 90.2 feet, and the critical depth within the culvert is 6.38 feet. On the right, the culvert outlet invert has an elevation of 78.79 feet; the E G L has an elevation of 88.46 feet; and the TW H G L has an elevation of 86 feet. The vertical drop from the E G L to the TW H G L at the exit is given by the product of K subscript o times the difference of the quotient of the square of V subscript o divided by the product of 2 times g, all minus the quotient of the square of V subscript TW divided by the product of 2 times g. One foot equals 0.305 meters.

Figure 162. Diagram. PC-B model, no corner fillets, Q subscript 100 elevations.

The diagram has three parts. The top part is labeled Section A-A and is a head-on view of a two-barrel inlet. Each barrel is 9-feet wide by 8-feet high. The corners of the barrels have no fillets. The middle part of the diagram is labeled Plan View. It is an overhead view of the culvert. Two diagonal slash marks across the culvert indicate the depiction of the culvert's length has been abbreviated in the diagram. The bottom part of the diagram is labeled Profile View and is a side view of the culvert with a number of elevations and a dimension. The dimension is the length of the culvert from the top of the entrance to the top of the exit and is 84.0 feet. Two diagonal slash marks across the culvert indicate the depiction of the culvert's length has been abbreviated in the diagram. The entrance to the culvert is on the left, and the exit is on the right. On the left, the culvert entrance invert has an elevation of 78.81 feet; the H W E G L has an elevation of 89.69 feet; and the E G L has an elevation of 88.56 feet. The vertical drop in the E G L as it enters the culvert is given by the product of K subscript e times the quotient of the square of V subscript e divided by the product of 2 times g. At the culvert's center, the roadway elevation is 90.2 feet, and the critical depth within the culvert is 6.26 feet. On the right, the culvert outlet invert has an elevation of 78.79 feet; the E G L has an elevation of 88.46 feet; and the TW H G L has an elevation of 86 feet. The vertical drop from the E G L to the T W H G L at the exit is given by the product of K subscript o times the difference of the quotient of the square of V subscript o divided by the product of 2 times g, all minus the quotient of the square of V subscript TW divided by the product of 2 times g. One foot equals 0.305 meters.

Figure 163. Equations. Brink depth at culvert outlet.

This figure contains four equations. The first equation is lowercase d subscript o equals the difference of E G L subscript o minus the quotient of the square of V subscript o divided by the product of 2 times g. The second equation is E G L subscript o equals the sum of E G L subscript TW plus h subscript L-o. The third equation is h subscript L-o equals K subscript o times the difference of the quotient of the square of V subscript o divided by the product of 2 times g, all minus the quotient of the square of V subscript TW divided by the product of 2 times g. The fourth equation is V subscript o equals the quotient of Q divided by the product of d subscript o times the total culvert width.

Figure 164. Equation. Headwater E G L.

H W subscript E G L equals the sum of E G L subscript U-S plus the product of K subscript e times the quotient of the square of V subscript U-S divided by the product of 2 times g.

Figure 165. Diagram. Net area used for backwater computations.

The diagram is a head-on view of a culvert. The culvert's four corners each have a corner fillet. The inside horizontal dimension of the culvert is labeled span. The inside vertical dimension of the culvert is labeled rise equal D. The water line is near the top of the culvert and partially covers the fillets in the top corners. The distance between the water line and the inside bottom of the culvert is labeled lowercase d. The vertical dimension of the bottom corner fillets is labeled lowercase A. The vertical distance that the top corner fillets are under water is labeled lowercase A subscript t.

TABLES WITH SKETCHES

Table 6. Summary of outlet loss coefficients.

This table gives the unsubmerged and submerged outlet loss coefficient, K subscript o, for eleven culvert barrel configurations, labeled a through k. The configurations are not described in words. Instead, they are presented as simple two-dimensional sketches. Each sketch is of one or more rectangles, which represent a head-on view of a culvert entrance. Here follows a description of each culvert barrel configuration, and the outlet loss coefficients for the configuration. In sketch a, the configuration is a one-barrel square culvert; K subscript o unsubmerged is 0.73 and K subscript o submerged is 1.12. In sketch b, the configuration is a two-barrel culvert, each barrel being square; K subscript o unsubmerged is 1.00 and K subscript o submerged is 1.11. In sketch c, the configuration is a three-barrel culvert, each barrel being square; K subscript o unsubmerged is 0.89 and K subscript o submerged is 0.96. In sketch d, the configuration is a four-barrel culvert, each barrel being square; K subscript o unsubmerged is 0.94 and K subscript o submerged is 1.08. In sketch e, the configuration is a three-barrel culvert, each barrel being square and the last barrel on the right being slightly separated from the first two; K subscript o unsubmerged is 1.07 and K subscript o submerged is 1.19. In sketch f, the configuration is a four-barrel culvert, each barrel being square and the two barrels on the right being slightly separated from the first two; K subscript o unsubmerged is 1.04 and K subscript o submerged is 1.03. In sketch g, the configuration is a one-barrel rectangular culvert with a 2-to-1 span-to-rise ratio; K subscript o unsubmerged is 0.66 and K subscript o submerged is 0.97. In sketch h, the configuration is a one-barrel rectangular culvert with a 3-to-1 span-to-rise ratio; K subscript o unsubmerged is 1.28 and K subscript o submerged is 1.35. In sketch i, the configuration is a one-barrel rectangular culvert with a 4-to-1 span-to-rise ratio; K subscript o unsubmerged is 0.85 and K subscript o submerged is 1.11. In sketch j, the configuration is a skewed three-barrel culvert, each barrel being square; K subscript o unsubmerged is 0.86 and K subscript o submerged is 0.99. In sketch k, the configuration is a skewed one-barrel rectangular culvert with a 3-to-1 span-to-rise ratio; K subscript o unsubmerged is 1.10 and K subscript o submerged is 1.26.

Table 13. Tests to analyze the effects of bevels and top edges.

This table contains 10 rows, each containing specifications and a sketch for a culvert inlet. Each sketch is a perspective, or three-dimensional, drawing, with the near portion of the inlet on the left side and the distant portion on the right side. The specifications pertaining to each sketch provide a description for it.

Table 14. Tests to analyze the effects of multiple barrels.

This table contains 21 rows, each containing specifications and a sketch for a culvert inlet. Each sketch is a perspective, or three-dimensional, drawing, with the near portion of the inlet on the left side and the distant portion on the right side. The specifications pertaining to each sketch provide a description for it.

Table 15. Tests to analyze the effects of the span-to-rise ratio.

This table contains 12 rows, each containing specifications and a sketch for a culvert inlet. Each sketch is a perspective, or three-dimensional, drawing, with the near portion of the inlet on the left side and the distant portion on the right side. The specifications pertaining to each sketch provide a description for it.

Table 16. Tests to analyze the effects of skew.

This table contains 6 rows, each containing specifications and a sketch for a culvert inlet. Each sketch is a perspective, or three-dimensional, drawing, with the near portion of the inlet on the left side and the distant portion on the right side. The specifications pertaining to each sketch provide a description for it.

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The Federal Highway Administration (FHWA) is a part of the U.S. Department of Transportation and is headquartered in Washington, D.C., with field offices across the United States. is a major agency of the U.S. Department of Transportation (DOT).
The Federal Highway Administration (FHWA) is a part of the U.S. Department of Transportation and is headquartered in Washington, D.C., with field offices across the United States. is a major agency of the U.S. Department of Transportation (DOT). The hydraulics and hydrology research program at the TFHRC Federal Highway Administration's (FHWA) R&T Web site portal, which provides access to or information about the Agency’s R&T program, projects, partnerships, publications, and results.
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