跌坎型底流消力池的水力特性与优化研究

本文以向家坝高水头大单宽流量水电站为例，对旨在降低消力池临底水力学指标的跌坎型底流消力池进行了系列水工模型试验，研究了不同跌坎高度的消力池水力学特性。研究成果表明，连续跌坎的采用有利于降低消力池临底流速，其应用效果取决于跌坎高度，但跌坎的存在也改变了消力池内的水流流态，对底板脉动荷载与消力池的消能效率有较大影响。对有溢流表孔与中孔的泄水建筑物采用适度收缩泄水孔出口的布置方式，可以起到稳定消力池水流流态、增进消能效率的作用，同时有利于减轻泄洪雾化。

Study on stilling basin with step-down floor for energydissipation of hydraulic jump in high dams

A new type of stilling basin with step-down floor for enhancing the energy dissipationof hydraulic jump in Xiangiaba Project is studied in model test. It is found that the step-down results in remarkable decrease of flow velocity and pulsating pressure acting on the floor, but at the same time, it affects the stabilization of flow regime in stilling basin. Series of model test with various heights of step are carried out to find out the optimal design for the Project. It also found that the energy dissipation efficiency is enhanced when the outlet sections of spillway and mid-level sluice are moderately contracted.