角木塘水电站非完全宽尾墩联合消能试验研究

Experimental study of joint energy dissipation with incompletely flaring pier in Jiaomutang Hydropower Station

角木塘电站最大单宽下泄流量达到211.2（m^3/s）·m,溢流堰前后最小水头差H仅有5.39m,属于典型的大单宽泄流量、低水头闸坝工程,此类工程往往具有低佛氏数、下游深尾水以及消力池内消能不充分等问题.结合物理模型试验,针对原跌坎消力池内尾水较深、入池水流剪切、摩擦紊动不足、消能效果较差等问题,提出趾墩等常规消能工以及非完全宽尾墩联合辅助消能工,并得出以下结论：非完全宽尾墩利用相邻闸室非对称挑射水舌,增强入池水流横向扩散,加剧消力池内水流紊动,有效调整消力池内下泄水流流场分布,明显消除原设计方案出池水流二次水跃,出池流速由原设计方案7.23m/s降低至4.43m/s,校核工况及常遇工况消能率由原设计方案的9.03%和33.03%分别提升至20.47%和58.75%.该方案能取得良好的水流流态和消能效果,可为类似低水头、大单宽流量工程提供参考.

Located in the downstream of Furongjiang River,Jiaomutang hydropower station is the typical large unit discharge,and low head discharging project with maxim large unit discharge 211.2 m^3/s·m and minimum head difference 5.39 m,and such projects often have obvious characteristics with low Froude number,deep tail water and insufficient energy dissipation.Aiming at the inadequate shear and friction in the stilling basin,this paper,by means of physical model test,comparing a series of conventional energy dissipator and proposed incompletely flaring gate pier,which made use of asymmetric water jets in the adjacent chamber to increase lateral diffusion and adjust velocity distribution in the stilling basin.Well flow pattern and energy dissipation effect are achieved with flow rate reducing from 7.75 m/s to 5.2 m/s in the outlet of stilling basin and energy dissipation rate of checking flood conditions and regular flood conditions respectively rising from 9.03%and 33.03%to 20.47%and 58.75%.