Experimental study on the shape of plunge pool in the Horizontal Swirl Spillway Tunnel

According to the study on the shape of plunge pool in the horizontal swirl spillway tunnel, the design scheme of a plunge pool with better energy dissipation effect is proposed. Based on the hydraulic physical model test, which includes atmospheric pressure and decompression tests, and combined with the different design scheme of a plunge pool, measurement results of fluctuating pressure. Main frequency and sidewall pressure are analysed. The results show that the inlet section of the plunge pool is connected by a gradual variable section which length of gradient segment 6m. The shape of the gradient section is a long round variable gate hole. To improve the side wall pressure, the inlet section is increasing from 6.0m to 14.0m. Finally, the proposed plunge pool has the advantages of simple design and convenient construction, and these studies provide reference and support for the design of hydropower dams in western China.