Research On Performance And Noise Reduction Of Engine Cooling Fan Based On Bionic Coupling

As a very important part of automobile,cooling fan has a direct impact on the working state of engine.On the one hand,in order to cool down an overheated engine,fans are required to have better heat dissipation.On the other hand,the fan should make as little noise as possible as it rotates.Therefore,the research on fan performance and noise becomes very important.The development of computers has accelerated the development of fan CFD technology.Compared with the traditional method,the most prominent advantage of CFD technology is that the flow field variation can be obtained in detail through numerical calculation as long as the three-dimensional model of the fan is designed.These information can not be obtained directly through experiments,and reduce the development cost of fans,so it is widely used.In this paper,a fan is selected for aerodynamic performance and noise test,and a CFD model is built.Simulation calculation is carried out by setting parameters such as calculation method and turbulence model.The calculated data show that the model is correct and sound field and flow field of the fan are analyzed.Through the study of bionic coupling theory,the diamond structure of shark skin and the pit structure of dung beetle shell surface were taken as the bionic prototype,and the structure was simplified and set on the pressure surface of the fan.A total of 7 fans were designed.The effects of coupling factors on aerodynamic performance and noise of fans are studied from the aspects of shape,arrangement and number of structures.The following conclusions are drawn:The aerodynamic performance improvement effect of the composite structure is better than that of the other two single structures.Moreover,the noise reduction effect of the composite structure is also significant.The sound pressure level of the fan decreases by 1.38dB.When the bionic coupling structure is arranged in a uniform way and the number is small,the static pressure of the fan will be increased,and the loss of shaft power will be reduced,and the power capacity of the fan will be improved.