Case study: Simulation and control of high frequency noise for commercial vehicle cab considering leak

To simulate the acoustic environment in the commercial vehicle cab realistically and improve the accuracy of predicting high-frequency noise, a statistical energy analysis (SEA) model considering the leak was created. The Bernoulli equation was used to derive the equivalent leakage area, and the total equivalent leakage area was distributed to each leak point based on leak contribution. The equivalent leak points were entered to the model for simulation, and the interior noise of the cab was predicted and validated under two working conditions. Results showed that the simulation accuracy was improved, i.e., error decreased by about 1.5 dB (A) and absolute error was less than 2 dB(A). Prediction precision was also satisfactory, and the effectiveness and reliability of the SEA model considering leak were verified. This study can provide a reference for establishing an accurate SEA model in the product-development stage in engineering. Interior noise was predicted under different leakage values, and the influence curve was obtained. Combined with influence curve and other factors, the appropriate leak value was determined to be 150SCFM. Main leak points were targeted for optimization and rectification. After optimization under two working conditions, the tested overall sound pressure levels of the interior noise decreased by 1.82 dB(A) and 1.31 dB(A). This finding showed that the measures taken in this article can achieve a good noise reduction result and can thus significantly guide the design and development of new vehicles.