The Effect of Geometric Change of Steps of Stepped Spillways on Hydraulic Characteristics of Flow using Finite Volume Model Flow3D

The study simulated the flow on ogee, stepped simple, and curved spillways using Flow3D flow numerical model, and the results of velocity change and energy loss were examined. Given the simulations done and observing the results and comparing them with the in vitro model results and considering the different flow conditions prevailing in these simulations, one can conclude that using Flow3D software in the analysis of free level problems can provide promising results. Comparison of the results obtained shows that the error rate of the results of the numerical model Flow3D with the in vitro numerical model was less than 5% on average. It is noteworthy that at the in vitro model, the primary depth cannot be properly measured because of the flow turbulence. Therefore, the energy loss was obtained by indirect method: firstly, the secondary depth of the hydraulic jump was measured and then the primary depth was calculated based on sequent depth equation, which can cause errors in the calculations. However, in the numerical model, not only are these steps not needed, but the numbers obtained were more reliable due to the precise determination of the primary depth.