某新开发自然吸气发动机车辆在加速过程中当发动机转速为2000 r/min左右时车内存在轰鸣声，严重影响车内乘坐舒适性。运用道路试验分析、CAE分析等手段对噪声产生的原因进行研究，最终确定原因是进气系统压力波动导致空气滤清器振动，经由车身连接点至车内传递路径放大导致轰鸣噪声。通过优化进气系统压力波动，增加赫姆霍兹谐振腔，降低激励源，并在车身与空滤连接点增加橡胶垫片以衰减振动传递，使车内前后排噪声幅值各降低7 dB左右。%There is a booming noise for a newly developed vehicle with a natural intake system when it is accelerating and the speed of the engine reaches 2 000 r/min, which seriously affects the NVH performance. In this paper, the cause of booming noise is analyzed by means of road test method and CAE method. It is found that the pressure fluctuation of the intake system induces the vibration of the air-filter. This vibration is transferred from the joint between the air filter and the car body to the monocoque and then amplified, which leads to the booming noise. Afterwards, the intake system is optimized by adding a Helmholz resonant cavity to reduce the pressure fluctuation. The rubber washer is added at the joint to attenuate the vibration transfer. Finally, the sound pressure level of the booming noise in the monocoque is reduced by 7 dB.
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