Volume 11 (2018) Issue 1 Pages 39-45
To improve the design of the splitter blade in the centrifugal pump impeller, inner flow numerical simulations are performed on the centrifugal pump impeller without splitter blades firstly, inner flow diagnoses are performed based on the theory of the boundary vorticity dynamics, and distributions of the boundary vorticity flux (BVF), friction force as well as vorticity on the inner walls of the impeller are carefully analyzed to find the location of bad flows and their dynamic sources. Later, according to the inner flow diagnosis results, splitter blades are designed and reformed for the original impeller. The inner flow filed in the impellers equipped with the preliminary splitter blade and reformed splitter blade are numerically simulated and diagnosed. Finally, comparisons are made among the three impellers, and it is found that, compared to the original impeller (impeller 0), the BVF, friction force and vorticity distribution in the impeller equipped with the preliminary splitter blade (impeller 1) has no obvious improvement, although the pump head increases, the efficiency decreases; the BVF, friction force and vorticity distribution in the impeller equipped with the reformed blade (impeller 2) has improved obviously, BVF peak decreases evidently and BVF distributes more uniformly, flow separation is inhibited, the hydraulic force acting on the impeller increases, with the pump head and efficiency increasing dramatically. It is proven that, flow diagnosis based on the theory of the boundary vorticity dynamics is an effective supplemental way for the design of the splitter blade in the centrifugal pump impeller, and will provide reference for the design of other turbo machinery as well.