Numerical Simulation Analysis Of Internal Flow Field Of Centrifugal Pump Based On CFD

Centrifugal pump is an important hydraulic machinery,in industry,agriculture and many other sectors of the national economy plays a key role.As a result,the performance index of the centrifugal pump differs greatly from the design value,and the centrifugal pump deviates from the design operation,resulting in the decline of pump efficiency and service life.With the development of computational fluid dynamics,numerical simulation of internal flow field of centrifugal pump is helpful to understand the operating principle of centrifugal pump from a deeper level.its research has a certain engineering practical value in promoting green,environmental protection and energy conservation.The main research contents are as follows:(1)analyze the influence of the inlet of different flow channels on the hydraulic performance of the centrifugal pump,and compare the inlet of the tapered,tapered and straight flow channels.It is found that the inlet of the tapered flow channel can improve the efficiency of the centrifugal pump.After the simulation comparison of four groups of inlet with different gradually expanding sizes,it is found that the efficiency of centrifugal pump decreases after the maximum value appears with the increasing of the gradually expanding degree.(2)Select 6 different blade number schemes respectively,and analyze the effect of different blade numbers on the hydraulic performance of the centrifugal pump after numerical simulation.As the number of blades increases,the pressure a nd velocity distribution in the impeller is more uniform,and the backflow phenomenon at the diaphragm is relieved,and the internal flow condition is improved.However,too many blades will cause the flow channel to narrow,and the blades will squeeze out the fluid,which will increase the impact loss at the entrance of the impeller and reduce the efficiency.(3)Four different turbulence models were used to numerically simulate the centrifugal pump under three different working condition.Comparing the static pressure field,flow channel and blade velocity distribution and turbulent kinetic energy distribution of different control groups,it is found that the SST k-? model has different deviations from the other three models in predicting the flow regime u nder different operating conditions.The standard k-? model and the Reallizable k-? model are used to simulate with higher accuracy under different conditions.