Numerical simulation of flow in bottom outlet of Narmashir dam for calculating of hydrodynamic forces

Mehdi Nezhad Naderi, Ehsanalla

Abstract

The bottom outlets are used to transfer water from the lake to the dam downstream. Performance analysis includes a discharge conduit, and outlet valve has a special sensitivity to them. In this Study is evaluated the pressure distribution around the outlet channels and the calculating of hydrodynamic forces was carried out. Numerical Solution carried out by Fluent software that is based on finite volume method. Then physical model results were compared with results of numerical models. Velocity and pressure values obtained from the numerical values of the pressure on the valve per valve opening of 30%,50% and 80%. The results show that the pressure values obtained from the numerical model and previous studies follow a similar pattern. For greater amount of percentage of gate opening the pressure exerted on the bottom and top of the valve opening is reduced. According to the results of previous studies and numerical model, always difference of pressure exerted on the bottom and top of the valve is caused down pull force.