导叶双列叶栅位置对水力性能的影响

Effect of tandem cascade position on hydraulic performance of Francis turbines

基于N-S方程和标准k-ε紊流模型,用数值模拟的方法分析了固定导叶和活动导叶的相对位置关系对水力性能的影响;主要分析了固定导叶出流角与活动导叶进水角的匹配关系,活动导叶的三种不同位置的速度矢量和压力分布,活动导叶的几何出水角与水流角的关系.在分析了三种不同位置时的水力损失后,给出了固定导叶与活动导叶的最佳位置关系,提出了双列叶栅设计时的最优设计参数.

Based on N-S equation and the standard k-ε turbulence model, the effect of the relative position of the guide vane and the stay gate on hydraulic performance of Francis turbine is analyzed by using numerical simulation method. The matching relationship between the stay gate outlet angle and the guide vane inlet angle is analyzed. In the guide vane, the relationship between geometry outlet angle and outflow angle, the velocity vector, the pressure distribution and the hydraulic loss under three different position conditions are researched respectively. In this paper, the optimum position between the guide vane and the stay gate is given and the optimum design parameters are put forward.