Optimization Design And Numerical Simulation Of The Centrifugal Pump

The centrifugal pump is extensively used in the all the aspects of the national economy and social life, which is playing an important role in the petroleum chemical, metallurgy, water supply and drainage and farming irrigation industry. With the development of the computer technique and computational fluid dynamics (CFD), the performance of the centrifugal pump must be met by the higher demanding. At the present, there are all variety of problems existing in the centrifugal pump development and design, which contributing to an undesirable result. For instance, the optimization is still stuck in the single-objective optimization without taking the matching relation between impeller and volute into count. Besides, the field simulation fails to analyze the impeller-volute coupled features. The study and achievement of the thesis can be a high instruction in fundamentally improving the performance and perfecting the theory on centrifugal pump design.In the thesis, considering a centrifugal pump with the specific speed 77 as the study objective, a multi-objective optimization mathematical model was established, in which energy loss, NPSHr performance and H -Q curve stability were involved. The 3-D flow field model was created and meshed according to the optimal solutions as well as specifying the boundary conditions. The numerical simulations, including internal flows and coupled features of the impeller–volute, were conducted in the Fluent, a CFD flow-field simulation software. Besides, the head and efficiency performance were also predicted and proved reasonable.Taking the matching relation between the impeller and volute into consideration, the theoretical head at the optimal condition was established. A multi-objective optimization mathematical model was established, in which energy loss, NPSHr performance and H -Q curve stability got involved. The target functions were unified with the weighted linear method on account of the importance of target function. The variable values range, suitable to the study, was confirmed.The optimal solutions of the centrifugal pump geometric parameters are also obtained under the help of the Matlab GA Tool-box. After the optimization, all aspects of the target objective had improved, in which energy loss decreased by 1130.7w, NPSHr reduced by 0.4258m and H -Q curve stability largely improved. Moreover, the results of the optimization were proved feasible after theoretical analysis.The 3-D model of the impeller and volute was created and assembled in the Pro/ENGINEER, a parameterization modeling software. The Gambit was adopted to mesh, check mesh qualities and specify the boundary conditions and fluid type. The numerical analysis data about the full flow field simulation and impeller-volute coupled features of the centrifugal pump were acquired in the Fluent.The post-processor of the Fluent was adopted to create the pressure contours, velocity vectors of the full flow-field as well as the coupled plane of the impeller and volute. The pressure and velocity distribution fluctuations were analyzed under the off-conditions. The pressure of the inlet and outlet and moment pivoting Z were exported from the numerical simulation data to make a performance prediction about the head and efficiency of the centrifugal pump, which proved the feasibility and soundness of the optimization and numerical simulation.In this thesis, combining the multi-objective optimization, genetic algorithm and flow-field numerical simulation of CFD, it can offer theory foundation and method reference to improve the performance and research the full flow-field of the centrifugal pump.