Analysis Of Vehicle Internal Noise And Optimization Of Vehic

Our study is based on the industrial-academic cooperation project, the optimization ofa domestic vehicle’s interiors, and used Statistic Energy Analysis (SEA) to predict vehicleinternal noise and optimize its sound package. We are focus on the influence of thegeometric CFD model simplification of each sub-system on the wind noise prediction, aswell as its influence on the final SEA model result. The content in detail is as following:1) Build up a SEA model including48structural sub-systems and203-D sub-systemsbased on the vehicles3-D geometric model. That can represent the acoustic characteristicsof the auto body well.2) Determine the model density and damping loss factors of each sub-systems usingthe method of analytical computation and FE analysis.3) Thought testing and measurement, we determine the engine sound radiatingexcitation and road excitations.4) Establish vehicle’s CFD model to determine the external wind excitations. Toevaluate the influence of the computational fluent dynamic model’s geometricalsimplification on its result accuracy. We build up a complex CFD model and a simplifiedone, and quantitative analyzed the influence of the sub-system’s geometricalsimplification on its wind excitation accuracy. That shows that influence of the frontwindshield is smallest while that influence of front door is largest.5) Input all kinds of parameters and excitations to SEA model, get the result about theinternal noise level and noise energy transmit route from the model. Verify the model viathe compare between the prediction and test result.6) Input the complex CFD model’s result and simplified model’s result to the SEAmodel respectively, thought comparing this2model’s result, we quantitatively analyze the simplification of each sub-system of CFD model’s influence on the SEA model’s finalresult. And that shows front windshield has the minimum influence while front door hasthe max one. That result can direct the CFD model simplification at some extent.7) Optimize the sound package of the front firewall via design of experiment. Theinternal noise has been decreased by1.52dB with the precondition of not increasing thetotal mass. That improves the vehicle’s noise isolating capacity.