Effect of head on the flow state of water in tailwater channel of the hydropower station

Abstract

Hydropower station tailwater channel is often prone to elevated water levels and insufficient energy consumption, which leads to the influence of the output of the unit. To study the intrinsic connection between the water flow state and elevated water level in the tailwater channel, this paper investigates the water flow characteristics inside the tailwater channel of the Mupo Hydropower Station under different heads and verifies the accuracy of numerical calculations by constructing a physical model test platform. The results show that the maximum velocity at the bottom of the fluid domain near the anti-slope section of the tailwater channel decreases with the increase of head, while the velocity at the top of the fluid domain near the anti-slope section of the tailwater channel does not change much with the increase of head; a large vortex is formed in the middle of the upper part of the fluid domain in the anti-slope section of the tailwater channel; and the lower the head, the more obvious the vortex is. The results provide guidance for the design of tailwater channels at hydropower stations.