Study On Doppler Effect Of Vehicle Noise And The Optimization Method Of Noise Barrier

Currently, the influence of road traffic noise on residents is serious, the main means of resolving the current traffic noise pollution is to build sound barrier next to the road, but the higher construction costs restrict its application. In addition, vehicle driving noise at high speed has the Doppler Effect, making noise barrier design more complex. To make the design arguments of sound barrier more reasonable, reduce construction costs, it is necessary to study Doppler Effect of vehicle driving noise and noise barrier optimization method.According to the principle of Doopler Effect and acoustic theory, this paper study the influence of vehicle driving noise Doopler Effect on receiver sound pressure level.Based on the analysis of the Doppler frequency shift influence on vehicle noise, this paper establish vehicle driving noise model of the Doppler Effect, and analyzed the factors affecting the Doppler Effect of vehicle driving noise. Research shows that the change of the sound pressure level and A weighted network frequency response resulted from Doppler frequency shift lead to difference in vehicle coming and leaving by the sound pressure level. As the vehicle speed higher, the influence of Doppler Effect more obvious. The sound pressure level of light vehicle with 120 km/h in coming is 2.3 dB(A) higher than that in leaving, the sound pressure level of heavy vehicle with 70 km/h in coming is 1.5 dB(A) higher than leaving.This paper study noise barrier optimization method based on vehicle noise Doppler Effect. By considering the effective length of traffic flow, as well as the day and night traffic noise sources deemed line source and point source is calculated separately, so traffic noise prediction model is more realistic traffic condition. With noise barrier position, height and both end extend length as design variables, the requirement of noise reduction as constraints, construction cost as objective function to optimize noise barrier design based on Doppler Effect. Research shows that the construction costs using optimization method is 5.13% lower than traditional method.This paper use the acoustic simulation software Raynoise to verify the effectiveness of optimization method. Acoustic simulation model is established by simulating traffic flow, vehicle Doppler Effect, sound barrier and other sound environment. The simulation result shows that the day and night equivalent sound pressure level and peak noise of received area can meet sound environmental qualitystandard. The simulation to traffic noise problem can provide references for noise barrier optimization design.