关键词: 汽车空调；低频噪声；仿真分析；试验验证

Abstract: This paper addresses the low-frequency booming noise issue complained by customers during the mass-production development phase of an automotive air conditioning project. A combined approach of experimental verification and simulation analysis was adopted to investigate the mechanism of this problem. First, experimental analysis is conducted to rule out the structural vibration of the heating, ventilation and air conditioning unit itself and the vibration transmitted along the transfer paths as the primary sources of the vehicle's low-frequency booming noise, thereby narrowing down the issue to the aerodynamic noise inside the heating, ventilation and air conditioning unit. Subsequently, simulation analysis is employed to identify the main noise sources as the backflow and vortex near the volute tongue at the volute outlet side. Accordingly, the system impedance is optimized to improve the fan operating point, and a rectification device is added to reduce backflow and vortex. Finally, the optimization scheme is verified through experimental tests, and the results demonstrated that the scheme significantly mitigated the low-frequency booming noise. The methods described in this paper can provide a reference for the optimization of noise issues in automotive air conditioning systems.

Key words: automotive air conditioning; low-frequency noise; simulation analysis; experimental verification