【摘要】 小型水轮发电机作为原动机能为工农业机械提供自主电源。为了使小型水轮机得到更广泛的应用 ,必须设计出结构简单、水力效率高的机器以确保运行稳定性。为此 ,对水轮机内部流动状况进行三维粘性流动数值解析是非常必要的。本文对常用的小型混流式水轮机涡壳、座环和无导叶环壁面内流动状况用最新的 CFD技术进行了整体数值解析。根据解析结果 ,对涡壳和固定导叶进行了改进以减少水力损失。亦对固定导叶入口冲角、涡壳壁面粗糙度对流动的影响进行了定量分析。更多还原

【Abstract】 As a prime mover, a small hydro turbine can produce the independence power for agriculture and industrial machines without fossil fuel. In order to extend its potential usage, the small hydro turbine should have a simple design with high performance to secure the stable operation. So, it is indispensable to investigate thoroughly the three dimensional viscous flow through the turbine. This paper deals with a lump-sum flow analysis of a spiral case, stay ring and vaneless annular walls for a small Francis turbine by the latest CFD code. According to the results of analysis, the shape of the spiral case and stay vanes were improved to reduce the hydraulic losses. Also, the chamfer of the stay vanes entrance and the surface roughness of the flow channel were optimized by the numerical investigations.更多还原