Evaluation of hydrodynamic forces on turbine ring gate during emergency shutdown process

This work uses numerical methods to investigate the hydrodynamic forces that act on a turbine ring gate during emergency shutdown. Accurately predicting the hydrodynamic forces on such gates is important because the forces constitute a design criterion of ring gates, especially in the case of the downward-pulling hydrodynamic force, which directly affects the opening or closing of the gate. In this article, we use Fluent, which is a computational fluid dynamics code, to simulate the flow patterns around the ring gate and to calculate the hydrodynamic forces on the gate. We numerically simulate the three-dimensional unsteady turbulence over the entire flow passage of the turbine. The numerical results show that the hydrodynamic forces are induced mainly by flow acceleration under the bottom surface of the ring gate. When the ring gate is at 90% closing position, the downward-pulling hydrodynamic force is maximal; near the completely closed position, the hydrodynamic force is more sensitive to the position of the ring gate. This investigation of the hydrodynamic forces that act on the ring gates provides the theoretical basis for determining the operational capacity and the optimal design of ring gates