Three-dimensional Numerical Analysis of Flow Pattern in Pressure Forebay of Hydropower Station

The feasibility of flow pattern in pressure forebay of hydropower station is studied by using computational fluid dynamics method (CFD). First, calculation is verified through typical examples based on Flow-3D of CFD software, and the good agreement between calculating results and empirical formula shows the accuracy and reliability of CFD method. Then, taking a specific hydropower station for an example, velocity distribution and the flow pattern variation of pressure forebay under three different operating conditions such as full load rejection, one-unit load acceptance and two-unit successive load acceptance are analyzed in details. The study shows that, at full load rejection and load acceptance conditions, the flow pattern at water inlet is good and water level fluctuation is steady although vortex shapes in a pressure forebay. It provides a basis for the hydraulic optimization design of pressure forebay.