高坝二级挑流消能研究

Study of Two-stage Ski-jump Energy Dissipation for High Dam

为研究高坝挑流消能的效果,结合四川省某水电站洞式溢洪道的大比尺水工模型试验,对在较高水头、较大流量工况下的溢洪道挑流消能形式进行优化研究。结果表明:通过将一级挑流改成二级挑流,即一级挑射水舌在各种工况下都挑落在平台上,水流通过平台形成二次挑流均匀挑入下游河道,可以有效分散消能,降低挑射水舌的高度,减小河床冲刷。采用二级挑流消能形式,有效地改善了原方案一级挑流消能引起的产生较大冲刷与雾化现象。

Combined with the large-scale hydraulic model test of the tunnel spillway of some hydropower station in Sichuan province,the optimization research on the ski-jump energy dissipation of the spillway under conditions of relatively high water head and relatively large discharge is introduced here.The test results indicate that the two-stage ski-jump energy dissipation,replacing the common one-stage ski-jump energy dissipation by the concrete terrace,could lead to more efficient dispersion energy dissipation,lower the plunging nappe height for spillway and lighten the scouring to downstream channel.The study results could provide references for the design of hydraulic structures under relatively high water head and relatively large discharge.