关键词: 混动皮卡；声学响应；进气空滤；进气声压；形貌优化；辐射噪声

Abstract: The intake sound pressure leads to the vibration of the air filter shell, which produces radiation noise. The radiation noise can be suppressed by optimizing the structure of the air filter. During the test of a hybrid pickup truck, it is found that there is an obvious roaring inside the engine at 2 000 r/min. According to the investigation of the roaring, it is found that the air filter shell roaring noise of the intake system is the main contribution source. In order to solve this problem, the air filter modal analysis and intake sound pressure spectrum calculation are conducted at first, and the result shows that the excitation of the sound pressure of intake of air filter can resonate with the vibration frequency of the air filter upper panel, resulting in increased noise in the vehicle. Secondly, through the topology optimization of the upper shell of the air filter, the optimal location of stiffeners is found, which greatly improves the modal frequency of the upper shell of the air filter, avoids the frequency of the maximum value of the sound pressure excitation spectrum, and eliminates resonance. And then, through the calculation of radiated noise, it is confirmed that the total sound power level of the optimized upper shell of the air filter is reduced by 8 dB(A), and the noise improvement effect is very significant. Finally, through experimental vehicle verification, it has been proven that this research method can effectively solve this similar problem.

Key words: Hybrid pickup truck; Acoustics response; Intake air filter; Intake sound pressure; Morphology optimization; Radiation noise