Modeling of the Flow Parameters of Chute Spillway with Change Slope (Case Study: Surk Dam Spillway)

One of the important issues in the design of chute spillway is to study the flow characteristics in the chute path because the flow is supercritical. In this study, the hydraulic characteristic of flow in the chute spillway of Surk dam has been investigated using both physical and numerical modeling. The plexiglass physical model was made with a geometry scale of 1:50 and FLUENT software was used for mathematical modeling. The experiments were carried out at 5 different discharges and the parameters of pressure, velocity and depth of flow were measured in the central axis and at the side of the wall. The results showed that among the measured parameters of FLUENT model, the velocity parameter was simulated with the lowest average error rate (4.3%) and the depth parameter with the highest average error rate (16.9%). Also, the Nash-Sutcliff coefficient and the correlation coefficient for the parameters, indicated that FLUENT software has a good ability to simulate flow characteristics over the chute spillway with a suddenly change slope. Regarding the RMSE and NRMSE criteria, FLUENT model have had the highest accuracy in calculating the flow parameters by using finite volume numerical method, turbulent model k-e, RNG, SIMPLE pressure correction method and VOF two-phase method.