Analysis And Improvement Of Passenger Car’s High Frequency Interior Noise Based On SEA Method

The automotive development cycle can be effectively shortened via numerical modeling, analysisand prediction to control automotive interior noise performance. Statistical Energy Analysis (SEA)method can be used to analyze the high-frequency noise. In the thesis, the prediction, optimizationand improvement on the interior noise of a passenger car are performed by using SEA.The passenger car and subsystems models are established according to the modeling principlesand assumptions of SEA, based on a cooperative project between college and enterprise. The materialproperties, physical attributes, modal densities, damping loss factors and coupling loss factors of eachindividual subsystem are calculated and determined in the models. At the same time, wind noise,which is calculated with CFD simulation, and engine noise, which is considered by the enterprise dataare as inputs in the SEA model of the passenger car.AutoSEA is employed to simulate automotive interior noise, of which the results are comparedwith those of road test, and the modeling effectiveness is identified. Then the simplification of thedivision to subsystems and the simulation of the simplified model are implemented. The simulativeresults comparing between simplified model and previous ones indicate that the division ofsubsystems has a great impact on the prediction accuracy of the SEA model.In order to analysis the interior noise of the passenger car the sound packages with differentsurface mass densities, the SEA models are simulated. The results show that it is no feasible just toimprove surface mass density to reduce interior noise, which violates the principle of lightweight.Finally, the contribution effects of improved the sound packages to interior noise are analyzed,and the sound package optimization is achieved with orthogonal test method, of which the effect isverified, reducing interior noise and lightening sound package.The research results in this thesis, show certain value as a reference to analyze acousticsperformance with SEA method and AutoSEA and to reduce interior noise without increasing soundpackage mass.