Prediction And Analysis On Passenger Car's Interior Noise Using Statistical Energy Analysis Method

Treated as the main kind of traffic tools, vehicles have played an important role in stimulating the modem city's development. But with the vehicles'quantity increasing, many problems appear and become more and more serious. The most serious one of them is the noise pollution released by vehicles, one aspect is due to that this pollution is become the main source of city's road noise and as the rapidly increased road traffics the proportion of vehicle noise is rising; another aspect is due to the damage that the vehicle interior's sound environment do to passengers directly in the situation that the car and bus has became an inevitable part of our life. So some helpful work is laying on how we can improve the vehicle's NVH performance and reduce its interior's noise to give people a comfortable circumstance.First, based on a domestic sedan for study, this paper uses Statistical Energy Analysis method to divide the vehicle body structure and vehicle interior cavity into 33 subsystems, and then builds this sedan's Statistical Energy Analysis model using its 3D CAD model data.Second, use theoretical calculations or experimental tests to gain the SEA model's three main parameters as various subsystems'modal densities, loss factors and coupling loss factors.Experimentally test this car's powertrain excitation energy to the body,road excitation input energy transmitted through suspension to the body and the excitation energy that the powertrain radiates on the body. Meanwhile, I do the CFD simulations on body surface air pressure fluctuations'excitation.Input the above parameters and excitation datas to the car's SEA modal and do its simulation, then I predict and analyze the noise sound pressure level by the driver and rear passenger's ears.With the comparison between simulation results and experimental results, I proof that the SEA modal on study car is correct.Finally, I use the verified SEA modal to simulate the car's acoustic design, analyze and discuss the influence on the car interior noise response at different sound absorption, sound insulation and damping materials, as well as different layout options.The outcome of this research can be referenced for sedan's interior acoustics packaging design.