台阶式溢洪道相对流速和相对消能水头的关系

摘要

Flow velocity and energy dissipation head are important hydraulic parameters in open channel flows. However,there is no systematic research achievement about it in stepped spillways so far.In this paper the con-cepts of relative flow velocity and relative energy dissipation head of stepped spillway were presented by comparing the velocity and energy dissipation head of stepped spillways with those of smooth spillways.Groups of tests were performed on stepped spillways with channel slope (38.66 °)and different step heights (0.5m,1.0m and 2. 0m).The measured data were analyzed and the results show that the relationship between flow velocity and energy dissipation head of non-uniform flow is complex,which is difficult to be applied,but the relative velocity of non-u-niform flow has good linear relationship with relative energy dissipation head in the presence of different unit width discharges and step heights.The correlation coefficient is 0.973 7-0.995 9.The results prove the necessity of in-troducing the concepts of relative flow velocity and relative dissipation head for stepped spillways.%流速和消能水头是重要的水力参数，但在台阶式溢洪道中尚无系统研究成果。将台阶式溢洪道流速、消能水头与对应光滑溢洪道流速、消能水头对比，引入相对流速、相对消能水头的概念。通过对0．5，1．0，2．0 m 3种不同台阶高度，38．66°坡度的台阶式溢洪道进行试验研究，探讨了流速、消能水头，相对流速、相对消能水头之间的关系。结果表明：非均匀流流态下流速、消能水头呈曲线关系，不便分析应用；相对流速和相对消能水头表现出良好线性关系，相关系数0．9737～0．9959，证实了引入相对流速、相对消能水头的必要性。