长短叶片混流式水轮机转轮内部流场数值模拟研究

多泥沙河流运行的水轮机的泥沙磨损一般都很严重,尤其是高水头混流式水轮机。本研究对一多泥沙河流上的高水头长短叶片混流式水轮机的内部流动特性进行了数值预测。数值结果表明,小流量和设计工况下,水轮机流场及压力分布均较为平稳,泥沙浓度最高区域位于叶片头部及出口靠近下环处,泥沙速度最高区域位于长叶片背面,设计工况下转轮长短叶片表面泥沙速度明显高于小流量工况。根据转轮叶片表面的泥沙浓度分布和流动特性情况,可以进一步预测水轮机转轮叶片的磨损情况,为多泥沙河流电站水轮机泥沙磨损研究提供参考依据。

Numerical Simulation of the Internal Flow Field of Francis Turbine Runner with Long and Short Blades

The sediment wear of hydraulic turbines running in muddy rivers is very serious,especially the high head Francis turbine.The internal flow characteristics of Francis turbine with long blade and long head on a muddy river are numerically predicted.The results show that,under small flow and design conditions,the flow field and pressure distribution of turbine are stable,the area with the highest sediment concentration is located at the head of the blade and near the lower ring at the outlet,the region with the highest sediment velocity is located on the back of the long blade,the sediment velocity on the surface of the runner blade under design conditions is obviously higher than that under small flow conditions.According to the sediment concentration distribution and flow characteristics on the blade surface of the runner,the abrasion of turbine runner blades can be further predicted,which serves as a reference for the study of sediment wear of hydraulic turbine in multi-sediment river power stations.