J. Sterling Jones Hydraulics Research Laboratory

Laboratory Physical Modeling

Force Balance Flume

The Force Balance Flume is 45 feet long and 14 feet in width. In this configuration, a discharge rate of more than 900 gallons per minute (gal/min) can be achieved. The flume has a force balance device that is used to determine lift and drag coefficients for water-inundated bridge decks. This flume can be easily modified into a wave channel by mounting a paddle to the existing two-dimensional (2D) shaker while the flume is filled with still water. It also has an apparatus that enables the measurement of movement of a bridge deck model using a motion-capturing technique and various sensors while it is being hit by waves. The flume utilizes a 2-axis robot to measure the velocity distribution using an acoustic Doppler velocimeter (ADV) probe.

Figure 1

The photo shows the 45 feet long and 14 inch in width Force Balance Flume looking from the downstream end. The photo also shows the flap gate to control the water level in the flume.

Figure 2

The picture shows the Force Balance Tower. A model of a bridge deck is mounted inside the Force Balance Tower and lowered into the Flume.

Fish Passage Culvert Flume

The Fish Passage Flume is 29 feet long and 18 inches in width. In this configuration, a 700 gal/min discharge can be achieved. The flume is tiltable up to 2.6 degrees. Different sections of a corrugated pipe can be inserted into the flume to measure and visualize the flow distribution at any cross section. The flume utilizes a 2-axis robot to measure the velocity distribution using an ADV probe. Two-dimensional, three- component (2D-3C) particle image velocimetry (PIV) can be performed in this flume.

Figure 3

The picture shows the Fish Passage Culvert Flume from the downstream end. The upper part of the flume is tiltable. The water falls over a flap gate into a tank under the flume.

Figure 4

The picture shows the channel of the Fish Passage Culvert Flume. A corrugated pipe is installed inside the channel and water runs through it.

Tilting Flume

The Tilting Flume is 70 feet long and 6 feet in width and has a sediment recess for highway-related scour experiments. The maximum discharge of this flume is 3000 gal/min. The flume utilizes a 3-axis carriage to measure the velocity distribution using an ADV probe and uses a laser distance sensor to map any scouring that has occurred in the sediment recess.

Figure 5

The picture shows the Tilting Flume from the downstream end. In the middle of the flume there is a recess filled with sand for scour experiments.

Figure 6

The picture shows the carriage from the Tilting Flume. The Carriage is a 3-axis robot resting on two rails on top of the tilting flume; it has an ADV probe and a laser distance sensor mounted to it.

Mini Culvert Flume

The Mini Culvert is 12 feet long and 10 inches in width. It has an open flume section which leads into a culvert. Stand pipes are distributed along the flume to measure the energy and hydraulics grade line along the passage from the open channel into the culvert. Optical Pressure Measurement (OPM) sensors are mounted to the stand pipes to measure the water pressure automatically. The culvert section can be replaced with a special culvert section that conducts 2D-3C PIV.

Figure 7

The picture shows the Mini Culvert Flume from the downstream end. On the right side along the flume there are stand pipes mounted.

Figure 8

The picture shows the stand pipes in the culvert section. OPM sensors are mounted on the stand pipes to measure the pressure inside the culvert.

Ex-Situ Scour Testing Device

The Ex Situ Scour Testing Device is 36 inches long and 14 inches in width. A special flow distribution can be archived within a 1 to 2 centimeter-high gap through the combination of thrust created by a moving belt and the normal pump pressure. In this configuration, a velocity of 6 meters per second (m/sec) can be achieved. Soil samples are mounted on shear and normal force sensor while pushed into the flow to account for the steady abrasion that occurs. 2D-2C PIV can be performed in this flume.

Figure 9

The picture shows the Ex Situ Scour Testing Device from a side view. A top box contains a belt drive with the test channel underneath it.

Figure 10

The picture shows the Shear Stress Sensor mounted at the bottom of the Ex Situ Scour Testing Device. A soil sample that is placed inside of it is pushed through the bottom of the flume into the test channel.

Particle Image Velocimetry (PIV) Flume

The PIV Flume is 25 feet long and 12 inches in width with a discharge rate of more than 200 gal/min. This flume is mainly used to measure and visualize flow along the cross section of bridge models using 2D-2C PIV. If necessary, a custom shaped Plexiglas sheet can be anchored at the bottom of the flume to simulate an existing scour.

Figure 11

The picture shows the PIV Flume from the upstream end. The picture also shows how the flume utilizes a vertical and horizontal trumpet shaped inlet to create a uniform flow.

Hydraulics Particle Image Velocimetry (PIV) System

The J. Sterling Jones Hydraulics Research Laboratory has the ability to perform 2D-2C and 2D-3C PIV in numerous flumes. In the past, the laboratory only utilized a 15 hertz (Hz), 100 milli Joule Yttrium Aluminium Garnet (YAG) Laser (120mJ YAG) and two cameras with 960 by 960 pixel resolution to perform PIV experiments. In the near future, an additional system will be available to perform 2D-2C and 2D-3C PIV with much higher speeds (200-300 Hz) and higher-resolution images (1280 pixels by 1024 pixels) using a new 200 watt laser and new high-speed cameras.

Figure 12

The picture shows a model of a bridge deck submerged in water. A cross-section of the bridge deck is illuminated by a laser. Particles within this light sheet are reflecting the light.

Figure 13

The picture shows a 2D-3C PIV setup. It shows two cameras mounted on top of the flume at an angle towards a cross-section of the flume. From the front, a laser illuminates the cross-section with a light sheet. Particles in the flow cross the light sheet and reflect the laser light.