Analysis And Optimization Of Aerodynamic Noise Of Sunroof And Side Window Of A SUV

In recent years,with the increasing speed of automobiles and the effective control of mechanical noise and tire-road noise,the level of aerodynamic noise has gradually become a key factor in determining consumers' purchasing choices and enhancing the overall image of the brand.Vehicle wind noise has always been the major comfort issues which consumers complaint about.The buffeting noise is caused by the pressure pulsation caused by the interaction of internal and external airflow in the driving,which directly affects the comfort of the vehicle.Therefore,it has important theoretical significance and application value for the study of aerodynamic noise of car sunroof,side window and rear-view mirror.This paper combines real vehicle road experiment and numerical analysis to analyze the buffeting noise phenomenon of the sunroof and side window when it is opened,and proposes effective optimization measures based on it.The main research contents are as follows:(1)Based on the N-S equation,the formula for calculating the aerodynamic noise is derived,and the empirical formula for effectively predicting the buffeting noise frequency of the sunroof is obtained.(2)The two models of the sunroof opening and the side window opening were simulated respectively,and the buffeting noise characteristics of the sunroof and side windows were analyzed,and the real vehicle road experiment was carried out to verify the comparison.(3)Based on simulation and experimental results,the buffeting noise of sunroof and side windows is optimized.By designing experimental methods,for the sunroof buffeting phenomenon,different sizes and angles of the baffle are designed to control the sunroof buffeting noise;for the side window buffeting phenomenon,by adjusting the flow channel at the rear mirror and the triangular window position,and absolutely optimizing it dimensions and mounting position to control side window buffeting noise.(4)The models of three different rear-view mirrors were simulated and analyzed,and the effects of three typical rear mirrors on the external flow field of the car were studied.Through the above analysis and optimization,after adding the deflector in the sunroof,the noise amplitude is reduced 18.2dB compared with the initial state,and the buffeting phenomenon basically disappears;at the left front side window area,the inside of the rear-view mirror plus a single row of diversion chute,the side window buffeting phenomenon is clearly suppressed and the noise is reduced 17.6dB.Both optimization methods have achieved obvious results,laying the foundation for future design and research work.