扭曲鼻坎对泄洪洞挑流消能的影响研究

针对某泄洪洞挑流水舌对下游河道产生不利影响等问题,开展了基于扭曲鼻坎调整射流方向的水力模拟试验研究。通过对几种扭曲鼻坎的优化研究,发现采用降低挑坎高程的大转角贴坡扭曲鼻坎布置,可以合理调整水舌方向,理顺下游河道形态,消除了右岸涌浪和边岸淘刷威胁,同时又解决了泄洪洞过渡期洞内水跃闷顶问题。研究成果对泄洪洞出流的消能防冲设计有一定的借鉴意义。

Study on impact from skew bucket on trajectory bucket energy dissipation for flood discharge tunnel

Aiming at the problem of the adverse impact from the trajectory nappe of a flood discharge tunnel on the downstream river channel， an experimental study of hydraulic simulation based on adjusting the jet-flow direction of the skew bucket is made. Through the research on the optimizations of several types of skew buckets， it is found out that if the layout of the skew bucket arranged on the slope with a larger turning angle on a lowered elevation of flip bucket is adopted， the direction of the trajectory nappe can be reasonably adjusted for straightening out the regime of the downstream river channel， and then the threat from the swell on the right bank and the bank erosion can be eliminated， meanwhile， the problem from the blocking of the hydraulic jump inside of the tunnel during its transition period can be solved as well. The study result has a certain reference value for the design of energy dissipation and anti-erosion for the outflow of flood discharge tunnel.