关键词: 纯电厢式微卡；轰隆声；导流罩；流体力学

Abstract: In order to resolve the problem of low-frequency rumble sound of a battery electric micro-truck at high speed, identified the characteristics and generation mechanism of the sound through computational fluid dynamics simulation and road test. The high-speed air enter the cavity of the air deflector through the gap between the container and cab, which exciting the self-excited oscillation and acoustic resonant coupling, which causes low frequency and high energy characteristics sound pressure inside the cab. The engineering scheme for optimizing the shape of the air deflector is finally determined by verifying the schemes of body structure strengthening, acoustic package coating, cargo compartment clearance adjustment, and shape optimization of the air deflector. According to the road test and evaluation of the actual vehicle, compared with the original basic state, the noise of the right ear in the 80～120 Hz frequency band is reduced by about 3.9 dB(A), and the problem is solved and it provides a reference for the subsequent aerodynamic noise optimization.

Key words: Battery electric micro-truck; Rumble sound; Air deflector; Computational fluid dynamics