台阶式溢洪道非掺气水流水面线的计算

台阶式溢洪道水面线是确定边墙高度的重要参数,目前尚无系统的研究成果.根据明渠非均匀渐变流理论,分析了台阶段水面线的计算方法;模型试验表明,用非均匀渐变流理论计算台阶式溢洪道非掺气水流水面线时,必须考虑局部水头损失的影响.经对比分析,台阶上的局部阻力系数ζ=0.5时计算水深和实测水深吻合良好.溢流反弧段水面线可以用动量方程给出的公式计算.同时,对于坡度为30°,51.3°和60°的WES曲线段,也通过模型试验给出了水面线的计算式.对比分析认为,本文给出的台阶式溢洪道非掺气水流全程水面线的计算方法简单,精度高.

Flow profile calculation of non-aerated flow on the stepped spillway

Although the flow profile is one of the most important parameters to determine the sidewall height of stepped spillway,there is no systematical research result about it.The calculation method of flow profile along steps is proposed,which is based on the theory of non-uniform flow in open channel.The model experiments show that the impact of local head loss should be considered when non-uniform flow theory is applied to calculate the non-aerated flow.The calculated data is consistent with the measured data when the value of local resistance coefficient is 0.5.The flow profile of the flip bucket can be calculated according to the equation which is derived from momentum equation.Also,the equations for computing the flow profile of WES curve segment within the range of 30° and 60° are obtained by model experiments.The results demonstrate that the calculation method for the flow profile of non-aerated flow along the stepped spillway is simple and accurate.