汽车空调出风口啸叫的辨识及机理探究

On the Identification & Mechanism of HVAC Outlet Whistle

通过近场测量法获得实车空调出风口啸叫的声压数据,并分析其频谱,又通过耦合气动-声学数值计算研究流场结构并探究啸叫机理。试验结果表明,啸叫的发生与空调出风口的风门位置和内外压差联系密切。当幅值-频域信号中2 k Hz以上部分存在明显的频谱峰值时,啸叫明显。啸叫产生的机理在于拟序涡结构脱落引发的有规律的压力脉动,辐射后形成较为规则的声压脉动。为预测啸叫、改进设计、预防啸叫提供理论依据。

By near-field measurements, sound pressure data of HVAC （Heating, Ventilation and Air Conditioning） outlet whistle can be obtained and the frequency spectrum is analyzed. By using numerical simulation of aero-acousticcoupled model, the paper studies the flow field structure and whistling mechanism. It can be drawn that the occurrence of whistling noiseis closely related to the throttle position and pressure difference. When obvious peaks exist above 2 kHz in the frequency spectrum, the whistling noise is remarkable.The mechanism behind whistling is that the pressure fluctuation resulting from coherent vortex shedding radiates and forms a regular sound pressure pulsation. The article provides a theoretical basis fbr whistle prediction, design improvement and whistle prevention.