Design and optimization of vehicle interior sound package

In order to reduce the sound pressure level (SPL) of the car interior noise at idle speed, the sound packages were analyzed and optimized. When the car interior noise was reduced, the weights of the sound packages were lightest at the same time. Acoustic characteristic prediction method of multi-layered porous materials was demonstrated. Some domestic car statistical energy analysis (SEA) model was built, the car interior noise at idle speed was predicted and verified by experimentation, the car optimization objective was determined at the same time. The contributions on interior noise were analyzed, and the result shows that the firewall has the greatest contribution to interior noise. The absorption coefficient of the firewall sound package was measured too. A new firewall sound package was designed with multi-layered porous materials, the absorption and insulation characteristic of the new design was contrasted with original sound package, the weight of the new firewall sound package was reduced by 0.8kg, and the interior noise reached the objective. The design and optimization result of the sound package shows that the absorption and insulation characteristic of the sound package with multi-layered porous materials can be improved, and the weight of the sound package can be reduced at the same time; the structure with multi-layered porous materials is a effective one to control interior noise and reduce the weight of the sound package.