Optimization Research Of Plastic Centrifugal Pump Cavitation Performace Based On CFD Flow Field Analysis

Plastic centrifugal pump can transport any consistence of acid-oxidants and other corrosive medium at a wide range of temperature, which has lots of advantages such as strong suction capacity, light working noise, no leakage, so the pump has been widely used. But one of the factors that affect plastic centrifugal pump performance, the cavitation, seriously blocks the high-speed development of plastic centrifugal pump. This paper consists both the efficiency and NPSH of plastic centrifugal pumps, simulated the internal flow field based on CFD flow field analysis to improve the overall performance of plastic centrifugal pump. The main contents are as follows:1. The two-dimensional hydraulic design of plastic centrifugal pump flow components was based on speed coefficient method, used the built-in module of CFturbo to complete the three-dimensional modeling of plastic centrifugal pump flow components.2. Numerical simulation and analysis of plastic centrifugal pump internal flow field was completed by CFD software Pumplinx based on computational fluid dynamic, and the efficiency and cavitation were forecasted.3. This paper selected the impeller inlet diameter, blade inlet angle, outlet angle and wrap angle as factors to design the orthogonal experiment, get the optimum combination of single quality evaluation by the range analysis, and simulation verified its rationality.4. On the basis of orthogonal experiments, this paper used Taguchi method to designed the orthogonal table, get the noise ratio of each level of each factor, then we got stability factors and adjustable factors by the range analysis, and the optimum combination of process parameters were gotten after the optimization of adjustable. factors. Simulation verified its rationality.5. The paper selected blade inlet diameter D1, impeller diameter D2, blade inlet angle β1, outlet angle β2, leaf number Z, impeller inlet width b1, and impeller outlet width b2 as design variables. We established a multi-objective function, and used matlab genetic algorithm toolbox for multi-objective optimization based on the genetic algorithm theory. The simulation results verified the feasibility of using genetic algorithm to optimize the parameters of plastic centrifugal pump.6. This part described the basic equation of pump NPSH, different transformation of the equation deduced the optimum impeller inlet diameter formula and the minimum NPSH formula, finally we established a pump NPSH predictive model.The paper simulated internal flow field of plastic centrifugal pump, in order to improve efficiency and reduce NPSH, four parameters of impeller were selected to design and complete the orthogonal experiment. We used the Taguchi method and the genetic algorithm to optimize the parameters, built a pump NPSH prediction model, and the overall performance of plastic pump was improved.