中文摘要：

在某抽水蓄能电站下水库泄流试验研究中发现,进出口高程差较小的明流泄洪洞在泄洪期能正常运用,但在泄水过程的某一阶段,泄洪洞中会出现水跃并在洞内游移：库水位下降,水跃上移、强度降低;库水位上升,水跃后移、强度增加。伴随水跃发展、跃后水深增加,很容易形成闷洞,直接影响过渡过程中的泄洪洞安全运行。另外洞末端射流顶冲下游河道防护堤,为了消除洞内水跃隐患并改善洞下游流态,提出了在泄洪洞末端挑坎段设置转角与侧堰的修改思路：通过弯曲挑坎调整射流方向,理顺河势;利用挑坎段环流控制侧堰分流抑制强水跃发生。试验表明在泄水过渡期内,侧堰充分利用环流特性,有效遏制了出口水深与水跃强度,避免了闷顶现象;同时弯曲挑流段也改善了射流角度与下游河势。

英文摘要：

In a series of experimental tests on a model of pumped-storage power station, this study has found that, a free-surface flow tunnel can generally be in normal use in flood period, but at certain phases of the water releasing process it generated a hydraulic jump that was moving along the flow. This jump normally moved upstream with its strength weakening if the reservoir stage was falling, while it moved downstream with its strength growing if the stage was rising. Its development in such movements could lower tunnel safety, because behind the jump is a water depth great enough to fully block the tunnel passage. In addition, at the tunnel outlet the jet flow was rushing forward onto the fending dike downstream. To avoid unfavorable effects of a moving hydraulic jump in the tunnel and improve the flow downstream, we suggested a modification on the flip bucket： adding both a turn angle and a side weir. Thus, by adjusting the direction of jet nappe closer to the river mainstream, taking advantage of the flow circulation on the flip bucket, and controlling flow diversion by the side weir, strong hydraulic jumps could be suppressed. Our test results show that in the period of transition between storage and drainage, the side weir can effectively curb both water depth at the outlet and intensity of hydraulic jump. Thus, tunnel blocking is avoided completely, and the jet angle and river flow around jet plunging are also improved.