基于两相流动理论的混流式水轮机叶轮内泥沙磨损的数值模拟

Numerical Simulation of Sand Erosion of Francis Turbine Runner Based on Two-phase Flow Theory

为研究长短叶片对水轮机两相流动的影响,选用RNGκ-ε湍流模型和混合多相流模型,针对混流式水轮机全流道在不同开度下的含沙水流两相流动内部流场进行数值模拟,分析长短叶片转轮和常规转轮内两相流动机理及不同转轮内的泥沙磨损状况。结果表明,长短叶片转轮改善了沙水在叶轮内的流动状态,沙粒体积分数在叶片上分布均匀,未出现大体积分数沙粒局部集中现象。研究成果进一步丰富了水轮机叶轮磨损的相关内容。

In order to analyze the influence of splitter blade on two-phase flow,RNGκ-εturbulence model and the mixed multiphase flow model were chosen to simulate two-phase flow filed of the whole Francis turbine flow channel under the conditions of different openings.Two-phase flow mechanism between the conventional blade and splitter blade was analyzed.Sand erosion of different runner was also analyzed.The results show that the splitter blade improves the sand water flow state within the runner,and the sand volume fraction distribute on the blades evenly.The large volume fraction of sand does not occur phenomenon of the localized concentration.The results further enrich the turbine runner wear related content.