Profile optimization of multi-diversion combination inducer and impeller

As the research objective is to optimize the performance of the combination multi-diversion inducer and impeller, this paper carries out the profile optimization study based on the correlation analysis of profile parameters with the structural parameters. Using the least square method, we obtained the fitting profile of the impeller, then compared the computational fluid dynamics (CFD) simulation results of the fitting model with the experimental results of the original model. The contrast shows that the error values of head and efficiency are less than 2%, and identifies the fitting method's accuracy. Finally, we compared the performances of the different fitting models through analyzing the correlation between fitting coefficient and impeller's inlet and outlet structural parameters. The results show that the internal flow fields of the three fitting models are stable. The impeller outlet and volute tongue have some low-pressure areas, and a certain high-speed group exists at the diffuse outlet because of the influence of vortex flow at the tongue. Ultimately, the head and efficiency of profile-3 are most optimized and obviously at the design point.