Abstract: In order to simulate the acoustic environment in the cab more truly and improve the interior noise prediction accuracy, the leakage is applied to SEA modeling and a commercial vehicle SEA model considering leakage is established. Bernoulli equation is used to derive the equivalent leakage area. The equivalent total leakage area is divided by the leakage contribution and added to the model for simulation. In contrast with the SEA model without considering leakage ,the results show that the simulation accuracy is improved and the error is reduced by about 1.5 dB (A) with the absolute error less than 2 dB(A), which meets the engineering requirement of high frequency noise analysis and prediction in vehicle product development and design stage. The SEA model considering leakage is fully validated. Under different leakage values, the interior noise is simulated and the curve of effect of leakage on the noise value is obtained. Combined with the influence curve and many other factors, the suitable leakage value of 150 SCFM is determined. The main leakage points are targeted for optimization and the leakage value drops from 268.5 to 149.1 SCFM. The interior noise after optimization is measured and the results show that the noise values are reduced by 1.82 and 1.31 dB(A) respectively under two working conditions compared with those before optimization.

Key words: interior noise, statistical energy analysis, leakage, equivalent leakage area