Optimum Design And Test Research Of Low-specific-speed Pump With Complex Impeller

The main energy conversion of low-specific-speed centrifugal pump is completed in the flow passage components such as complex impeller. So there is great significance for the optimum design of complex impeller to do the energy-saving of centrifugal pump. And the rapid development of CFD technology provides a powerful means for optimum design of low-specific-speed pump with complex impeller. Basing on the existing foundation of research team, the optimum design of complex impeller with long and short blade is obtained for efficiency improvement by the analysis of three-dimensional flow; moreover, the paper has some research on the numerical simulation and performance forecast of low-specific-speed centrifugal pump with complex impeller, and the test research of centrifugal pump with the optimum complex impellers. The following contributions have been made in this dissertation:(1) The method of optimum design and numerical simulation are introduced; The three-dimensional solid modeling of the flow passage components like inducer, complex impeller and volute are completed by three-dimensional modeling software Pro/e; using the NUMECA software the centrifugal pump is meshed by structured grids;(2) The parametric modeling of complex impeller is obtained by the fitting of the meridians curves and blades surfaces; there are two optimization strategies, one has both discharge angleβ2 and inlet diameter of short blades Di2 as the optimum parameter and the other has only discharge angleβ2; the optimum design of single periodic complex impeller is done for the efficiency improvement by the optimization strategies; and the optimum impellers geometry which have higher efficiency are obtained and used to draw and process;(3) Using the Spalar-Allmaras turbulence model and the Reynolds-Averaged Navier-Storkes equations, the simulation of low-specific-speed centrifugal pump with initial and optimum impellers are done for the flow field analysis of the flow passage components. The performance forecasting of low-specific-speed centrifugal pump with initial and optimum impellers are obtained, it is found that the efficiency of optimum one has been improved.(4) Experimental study is carried out to the centrifugal pump with initial and optimum impellers. The performance curves are obtained and compared with the result of numerical simulation. Through the experimental research it can found that the efficiency of impellerⅠ and impellerⅡare improved and the method of impeller optimization is issued to be useful.