Research On The Application Of Active And Passive Noise Reduction Methods In Vehicle Wind Buffeting Noise Control

The noise environment in the car has a direct impact on the ride comfort and has become the focus of attention at present.Wind buffeting noise,as one of the main noise sources of automobiles under high-speed working conditions,can easily make drivers and passengers feel tired and uncomfortable,and seriously affect the driving experience.At present,the control of wind vibration and noise mainly adopts passive noise reduction,that is,by changing the body structure,installing aerodynamic accessories and other means to affect the flow field during the operation of the car,so as to achieve the effect of noise reduction.However,this method can only be designed for specific working conditions.When the operating conditions of the car change,its noise reduction effect is still to be discussed.Active noise reduction is a method of destructive noise reduction through sound wave interference.The noise reduction effect depends on the spectral characteristics of the signal itself.It has shown good noise reduction in the control of vehicle interior noise(such as engine and tire noise)effect.However,there are relatively few studies on the active control of vehicle wind vibration and noise.Therefore,in view of the problems of the above active and passive noise reduction methods in wind buffeting noise control,this article has carried out research from the following aspects:(1)Carry out real-vehicle road tests to collect wind buffeting noise signals near the ears of drivers and passengers at different openings of the left front side window and the left rear side window at different speeds.The spectrum characteristics of wind buffeting noise at various points in the vehicle compartment are studied,and the first-order frequency and peak sound pressure level of the wind buffeting noise near the driver’s ears are analyzed.(2)Based on the improved large eddy simulation(LES)method and the Detach eddy simulation(DES)method based on the weak compressibility factor to carry out the numerical simulation of wind vibration and noise,compare the actual vehicle test data,select the high-precision Numerical simulation methods are used as the basis of this paper.(3)Taking extreme conditions as the design conditions,design the jet structure outside the B-pillar,use genetic algorithm to optimize the variable parameters of the jet structure,and obtain the optimal jet structure under the design conditions.This structure can give a shedding vortex perpendicular to the body The initial velocity component throws the shedding vortex to the outside of the car,reducing the probability of it colliding with the rear edge of the car window,thereby reducing the sound pressure level of wind noise near the driver’s ears.The noise reduction effect of the structure under non-design conditions is analyzed through numerical simulation,and its applicability in multiple operating conditions is studied.(4)In-depth study of the single-point wind buffeting noise active noise control(ANC)system algorithm of the driver’s right ear,and put forward the corresponding problems in view of its low modeling stability,large steady-state error,and poor noise reduction performance.The optimization strategy is based on the wind buffeting noise data obtained by numerical simulation,and the algorithm before and after optimization is simulated and compared to verify the effectiveness of the optimized algorithm.(5)Carry out wind buffeting noise active noise reduction research under actual vehicle conditions,consider the acoustic feedback effect,study its compensation strategy,and combine the optimized wind buffeting noise ANC system algorithm to establish a system that can simultaneously control the secondary channel Algorithm for online modeling with acoustic feedback channel.The simulation analysis is carried out on the basis of the wind buffeting noise data collected in the actual vehicle test to verify the noise reduction effect of the algorithm under multiple working conditions.