中型拱坝表孔大单宽流量泄洪消能形式的研究

Study on Dissipator of Large Discharge Per Unit Width for Crest Spillway of Medium Arch Dam

以龙潭嘴水电站工程整体水工模型试验资料为依据,采用表孔高低坎+二道坝研究了中型拱坝表孔大单宽流量泄洪消能形式。通过调整边、中表孔挑坎的位置高程及挑角来实现三孔水舌上下对撞和横向扩散碰撞消能。为达到水舌落点纵向拉开的目的,增大中表孔溢流曲线的长度,使中边表孔挑坎在纵向上形成差动。试验结果表明,在该消能形式布置下,水舌纵向拉开、横向扩散充分、对冲明显,同时在水垫塘内充分翻滚消能,对下游河道减轻了冲刷,消能效果较好。

Base on the experimental study on hydraulics model of Nongtanzui hydropower station,energy dissipation of high-low bucket subsidiary dam is used to study on the dissipator of large discharge per unit width for crest spillway of medium arch dam.In this experiment,by adjusting the elevation and bucket angle of flip buckets on three surface holes to achieve energy dissipation of water jets impact in air.In order to reach the purpose that water jets impact point vertical undrawn,the length of overflow curve of the middle outlet is increased to make flip buckets of middle and edge surface holes form differential in vertical direction.The results show that in the arrangement mode,the nappe is fully diffused in the horizontal direction and flushed obviously,as well as fully tumbled to reach energy dissipation in plunge pool,in which erosion of river downstream is reduced and the effect of energy dissipation is better.