Simulation Analysis And Control Of Automobile Aerodynamic Noise Based On Hybrid FE-SEA Method

In recent years, the efficient velocity of automobiles improved continuously,which lead to aerodynamic noise problem becoming more and more prominent.Solving the problem of aerodynamic noise will greatly improve the overall of the car brand and consumers desire. As the car was traveling at a high speed,the dipole sound source generated by the pressure pulsation of the outside air flow of the vehicle is generated by entering the inner cavity of the vehicle through the sound surface of the vehicle.This high strength and full band noise will discomfort people a lot and thus cause a seriously bad effect on their attitude toward the comfort performance. Vehicle aerodynamic noise is a full frequency distribution of the noise, and the current domestic and foreign of automobile air dynamic noise numerical study cannot achieve full band accurate simulation and, therefore, difficult in the research and development stage make corresponding to the noise reduction measures.Therefore, it is of great significance to find a simulation method that can accurately calculate the whole frequency band of the aerodynamic noise in the vehicle.This paper study on Full band of aerodynamic noise in vehicle under the high speed condition, combined with three methods of the real vehicle road test, wind tunnel test and FE-SEA hybrid model numerical simulation.On this basis,an effective noise reduction optimization is proposed.which achieved good results. The main research contents are as follows:1.Experiment a road test for a given car, select the two ears of the driver as monitoring points, study the sound level of the aerodynamic noise changed under different velocity conditions.2.When calculates the aerodynamic noise inside the car, we should also consider the effect of surface pressure convection section and the sound field. In order to accurately calculate the aerodynamic noise inside the car, discusses the computational fluid dynamics(CFD) describing the surface characteristics of the fluctuating pressure, prediction of internal noise analysis process, and focus on the distinction of the different characteristics of the surface pressure convection section and the field part, analysis the different frequency bands and inner air dynamic noise sensitive degree of two kinds of incentive. By comparing the numerical simulation results with the wind tunnel test results, the accuracy of the simulation calculation is proved.3.The hybrid FE-SEA simulation technology realizes the interior aerodynamic noise full band numerical calculation and compared the simulation results with the traditional calculation method and the real vehicle road test results. It is proved that the accuracy of the method and efficiency.4.On the basis of previous research, first of all, calculation and comparison of the contribution of aerodynamic noise by the key components of the external parts, find out the key components of the pneumatic noise, and the optimized design, so as to reduce the external noise effect, at the same time, to obtain the driver’s head with acoustic sensitive components, comparing the sensitive component monolayer arrangement sound-absorbing material and multilayer material properties, material quality, noise reduction and noise reduction efficiency, material price, price evaluation index; multiobjective optimization of multilayer absorbing material and then perform better overall performance, obtained the best combination of thickness of each layer of material eventually, two noise reduction optimization method combined reached good noise reduction effect.