高拱坝表孔挑坎水力特性的数值模拟研究

Numerical simulation research on Hydraulic characteristics of flip bucket of surface spillway of high arch dam

本文对高拱坝坝身表孔多种型式的挑坎进行了数值模拟计算,对流道内水深、压强、流速分布以及挑坎结构对孔口泄流能力的影响等分别进行了研究。结果表明,宽尾墩较大幅度地增加了流道的水深与压强;楔形体挑坎则可以在不明显增加流道水深与压强的前提下,对水舌进行纵向拉伸;而底板镂空型的楔形体挑坎能够进一步减小挑坎水深与压强。各挑坎末端最大流速及平均流速均差异不大,但是出挑水舌的挑角有较大的差异;同时,各挑坎体型对流道泄流能力不造成影响。研究成果可为高拱坝表孔挑坎的选型提供一定的参考价值。

Numerical modeling was used to calculate different kinds of flip buckets of surface spillway of high arch dam.Water depth,pressure and velocity distribution in the flow channel,towards with the influence on discharge capacity of the orifice by the bucket structure,were fully studied.Results show that,flaring pier could drastically increase the water depth and pressure of the flow channel.The bucket with wedge shape could lon-gitudinally extrude the plunging jet without clearly increasing water depth and pressure of the flow channel,and the wedge shape bucket with hollow flat on bottom could further decrease the water depth and pressure.The maximum velocity and mean velocity at the end of bucket have slight difference of each flip bucket,but the angle of ski-jump nappe has a remarkable difference.What ＇s more,the discharge capacity of flow channel has nothing changed by different flip buckets.The research result can provide some useful reference for the choice of flip bucket of surface spillway of high arch dam.