Spillway Flow Modeling by Finite Volume Solution of Slopping Depth Averaged Equations on Triangular Mesh; Application to KAROUN-4

摘要

The results of a numerical analyzer for solving super critical free surface flow in chute spillways with steep slope are presented in this paper. The developed model consists of depth averaged equations for flow on surface with steep slope toward one of the main horizontal axes of Cartesian coordinates. The depth-averaged form of the flow equations converted to discrete form for unstructured meshes using the cell vertex finite volume method. Therefore, the horizontal mesh is firstly transformed into inclined coordinate system. Then the discrete formulations are solved on the transformed mesh. Having computed the velocity vector parallel to the bed surface and flow depth perpendicular to the bed surface, the model computes three components of the velocity in Cartesian coordinate system as well as the water depths parallel to the z axe in vertical direction. The develop model is utilized for simulation of various flow regimes in prismatic canals, which have two different constant bed slopes in certain direction. The numerical results present the ability of the model to simulate very high speed super-critical flows in very steep bed slopes. Finally, application of the developed model on simulation of sub and super critical flow from reservoir to steep chutes and ski jump flip bucket spillways of KAROUN-4 in KHOZESTAN province of IRAN produced encouraging results.