基于CFD的转轮叶片对虹吸式水轮机水力性能的影响分析

为了更加高效地利用超低水头水力资源,设计了一种采用虹吸式出水流道的轴流式水轮机。针对这一形式的水轮机,在设计水头和额定转速下采用CFD进行三维数值模拟,计算各过流部件的水力损失,研究水轮机的水力性能。通过改变转轮叶片出水边翼形,对比分析转轮出口水流流态与虹吸式出水流道水头损失的关系,研究不同叶片对虹吸式水轮机水力性能的影响。结果表明,在水头、转速和导叶开度相同的情况下,各修改方案中叶片3使得出水流道水头损失较小,其对应的平均涡角为13.26°,出水流道水头损失为0.135 m,水轮机的效率也较高(为89.33%)。此外,选取效率较高的叶片,改变叶片数量,分析其对虹吸式水轮机水力性能的影响。

Influence of runner blade on hydraulic performance of siphon turbine based on CFD

In order to efficiently utilize the ultra-low head water resources, an axial flow turbine with a siphon outlet conduit was designed, and three-dimensional CFD numerical simulations were conducted with the design head and rated runner speed. The hydraulic loss of each flow passage component was calculated to study the hydraulic performance of the siphon turbine. The relationship between the flow regime at the runner outlet and the head loss of the outlet conduit was analyzed by changing the runner blade airfoil, and the influence of different runner blades on the hydraulic performance of the siphon turbine was studied. The results show that, with a constant water head, runner speed, and guide vane opening, the head loss in the outlet conduit of the turbine in the modified scheme with the third blade is at a minimal value of 0. 135 m, the corresponding average swirl angle is 13. 26o, and the turbine efficiency is at the maximum(89. 33%). In addition, the influence of the number of blades on the hydraulic performance of the siphon turbine was analyzed through selection of the blade with the maximum efficiency.