通过对轴流转桨式水轮机四种不同支墩的蜗壳数值模拟,研究结果表明:从水轮机转轮室进口来流的均匀特性来看,蜗壳支墩的个数和形式对水轮机的水力要素和性能影响较大;叶道间的流量沿导叶高度方向自顶盖至底环逐渐增大,支墩和蜗壳的形式对鼻端附近固定导叶和蜗形进口附近的活动导叶叶道间的流量具有一定的影响。支墩尾部自底环至顶盖扭向蜗型的部分能够将水流很好的引向蜗形部分,使水流在圆周方向上的分布更加均匀,有利于提高水轮机的整机效率和机组运行稳定性。
A 3-D numerical simulation of steady flow in the full scroll passage of a Kaplan turbine was conducted to study the effects of four different types of scroll buttress.The results show that the number and shape of scroll buttresses produce a great effect on the hydraulic parameters and turbine performances,particularly on the uniformity of vertical inflow profile at the runner inlet where the flow rate in the vane spacing increases in upward direction.This effect can extend to the flow rate in the spacing of stay vanes.The buttress tail that twists toward the worm inlet,could effectively guide the flow toward the worm and distribute the flow more evenly along the circumference.Thus through a better design of scroll buttresses the efficiency and stability of hydraulic turbine is improved and the life of turbine will be extended.