低比转速叶轮内部流动的数值计算

Numerical computation of inner flow in low-specific-speed impeller

为了解复合叶轮内部流动特性,采用雷诺时均Navier-Stokes方程和Spalart-Allmaras湍流模型对4长叶片的普通叶轮和4长4中8短16叶片的复合叶轮内部流动进行了数值模拟,得到了设计工况下两种叶轮内部流场分布,分析了中、短分流叶片对叶轮内部流场的影响。计算结果表明:采用长、中、短叶片设计的复合叶轮可以改善流道内流场分布,提高长叶片吸力面压力,有效地阻止液流的脱流,复合叶轮可以获得更高的静压差,有效地提高了离心泵的扬程。

Aiming at realizing the inner flow performance of complex centrifugal impellers, the Navier-Stokes equations and the Spalart-Allmaras turbulence model were carried out to simulate the inner flow field in low-specific-speed complex centrifugal impellers with four-long blades and four-long four-middle eight-short blades. The distributions of velocity and pressure were obtained, and the properties of inner flow inside the volute were also analyzed. The calculation result shows that middle and short blades can improve distribution of the velocity and pressure in inner flow field, increase the suction side pressure and prevent liquid separation from suction side in complex impellers. Complex centrifugal impellers can get higher static pressure rise and improve the performance of centrifugal pump.