Investigation ofCavitation in Stepped Spillway of Siah-Bishe Dam by Using Flow-3d Model

ABSTRACT: Cavitation is aphenomenon which damages and makes hole in hydraulic structure in high velocity and over-turbulent flows. In this research, stepped fast water formula of Siah-Bishe spillway is stimulated via Flow-3d software and compared with physical model. This software is an accurate tool in analyzing unsteady 3D flow problems with free surface and complex geometry. It solves problems by solving conservationof mass formulas, momentumand energy viafinite volume method. In this study, pressure parameter at the beginning, end and along the spillway is studied and negative pressure is observed in some parts. This pressure can make cavitation. The study shows the results of correspondence between physical model and finite volume method modeled by Flow-3d.