Determination of position of hydraulic jump in a flume by using CFD and comparison with experiential results

Abstract

Dams and hydraulic structures are used for the supply and control of water, which have great importance on human life. The sluice gate is one of the hydraulic control structures. Sluice gates release excessive water from the reservoir to the downstream side in a controlled manner with a certain discharge for controlling the level of the reservoir. A hydraulic jump is created to dissipate the energy of flow coming from under the gates. A hydraulic jump occurs when flow regime is changed from subcritical to supercritical. However, the position of the hydraulic jump in channel should be known exactly in order to prevent damage to surrounding structures. In this study, an open channel system with a sluice gate is used to produce a hydraulic jump. Experiments are conducted for two different gate opening (a1=1.5 cm and a2=2 cm) and 16 discharge values. For each case position of the hydraulic jump is determined. In addition, flow depths at 5 different points were measured including before and after hydraulic jump. The results obtained from the experimental study were compared with the numerical model in terms of the position of hydraulic jump and flow depths. According to the results obtained, the numerical model and the physical model showed between 80% -91% consistency.