Study on The Characteristics of the Twisted And Beveled Bucket of the Outlet of the Spillway Tunnel

Downstream river channels of hydraulic projects with a high velocity of 50m/s are prone to scouring, jeopardizing the river bed and hydro-ecosystem.In order to address this issue, a twisted and beveled bucket is proposed in this paper. Combining model tests with numerical simulations, the results showed that the bucket configuration can solve the problem of energy dissipation and can adapt to a large number of inflow conditions. In order to investigate the hydraulic characteristics of the flow in the spillway tunnel with bucket and reveal the effects of the complex structural characteristics on the overflow,two main parameters, the turning radius of the left wall of the bucket and the corner of the bottom plate, were selected for comparative tests. Through the analysis of the jet shape, distance, angle and range of the falling water, the influence of these two parameters on the flow properties and the response of the downstream river were obtained. It is found that, with the increase of the bucket angle, the lateral width of the bucket gradually decreased, the longitudinal diffusion gradually increased, and the diffusion section of the bucket was improved. By changing the turning radian and radius of the bucket side wall, the direction of water jet can be adjusted reasonably, the flow pattern of downstream river can be improved to a steady condition, and the threat of right bank surge and bank scouring can be eliminated, which can provide reference for engineering design.