具有前置诱导轮的低比转速复合叶轮的数值模拟

The Numerical Simulation of Low-Specific-Speed Complex-Impeller with Inducer

选用Navier-Stokes方程和Spalart-Allmaras湍流模型分析诱导轮对复合叶轮内部流动的影响,采用Numeca软件对具有前置诱导轮及无诱导轮两种工况下的低比转速复合叶轮进行了数值模拟研究。对比分析结果表明:与无诱导轮的叶轮相比,前置诱导轮复合叶轮叶片进口前端和叶片流道间回流区域减小,叶片进口处压力增加,叶轮内部液体流动更加均匀并提高了叶轮的抗汽蚀性能,有效改善了叶轮的水力性能。

In order to analyse the infulence of inducer on the flow in the complex impeller,the inner flow field in low-specific-speed complex impeller with and no-inducer are simulated respectively.Using the Spalar-Allmaras turbulence model and the Reynolds-Averaged Navier-Storkes equations,the three-dimensional turbulent flow fields are analyzed numerically by the Numeca Software.The results show that there is long and narrow back flow region near the inlet of blade and the performance is affected by the existence of the back flow in the channel between the blades in the complex impeller without inducer.While in the complex impeller with inducer,the inducer can effectively reduce the size of the back flow near the inlet of blade,the head generated by inducer can increase the inlet energy of blade,thus the cavitation performance of complex impeller can be improved and the back flow is decreased in the channel between the blades of complex impeller,the inner flow is more uniform.