关键词: 涡轮泵;离心泵;叶轮;数值仿真

Abstract: The Navier-Stokes equations and the Spalart-Allmaras turbulence model are adopted to simulate the inner flow field in high-speed complex centrifugal impellers with eight and twenty-four blades,respectively.The relative velocity and pressure distributions are analyzed and compared in the flow channel of two impellers under small-flow and design-flow condition.It is found that the velocity distribution of inner channel and outlet in complex impeller with four-long,four-middle,sixteen-short blades are more uniform than that with four-long,four-middle blades.And the middle and short blades can increase the suction-side pressure and prevent liquid separation from suction side in complex impellers.Through the experiment and simulation,it is validated that the back flow in impeller channel is a key factor which affects the efficiency and small-flow instability of low-specific centrifugal pump and centrifugal pump with closed complex impeller with long,middle and short blades can be used to deliver small-flow high-head liquid media.

Key words: Turbopump;Centrifugal pump;Impeller;Numerical simulation