Research On Aerodynamic Performance Prediction Of Micro Centrifugal Fan

With the development of electronic equipment towards high performance and miniaturization,there are higher requirements for its cooling components.It is very important to design a suitable micro centrifugal cooling fan.In order to improve the optimization design efficiency of micro centrifugal fan,this paper studies the aerodynamic performance prediction of micro centrifugal fan.Firstly,the basic governing equation of fluid motion,MRF model and turbulence model are introduced,and on this basis,the finite element model for predicting aerodynamic performance of micro centrifugal fan is established.The maximum air volume,static pressure-air volume curve and static pressure efficiency-air volume curve of centrifugal fan are obtained by calculation.Compared with the test results,the error of air volume prediction is less than 5%.The prediction error of static pressure increases with the increase of air volume,and the maximum relative error is about 5%.The variation trend of static pressure efficiency is also consistent with the experimental results.It shows that the numerical simulation method can accurately predict the aerodynamic performance of micro centrifugal fan.Secondly,mathematical model method is used to predict the aerodynamic performance of the micro-centrifugal fan,and 20 structural parameters of the centrifugal fan are related to its performance.A BP neural network model for predicting the air volume of centrifugal fan is established.Compared with the experimental results and the numerical simulation results,the feasibility of BP neural network to predict the centrifugal fan air volume is verified.On the basis of the existing flow loss calculation formulas at home and abroad,a loss model suitable for micro centrifugal fans is established by modifying the loss coefficients with the method of multiple regression based on 30 groups of experimental data.The static pressure-air volume curve and static pressure efficient-air volume curve of four micro centrifugal fans are predicted quickly and accurately,which can provide effective reference for the initial design of fans.Finally,by comparing the results of the two prediction methods,it is found that the two prediction methods can accurately predict the aerodynamic performance of micro centrifugal fans.The prediction accuracy of the numerical simulation method is higher than that of the mathematical model method,but the prediction efficiency of the mathematical model method is higher,which can save a lot of time of threedimensional modeling and meshing.In the initial stage of centrifugal fan optimization design,the efficiency of optimization design is greatly improved.