噪声与振动控制2018，Vol.38Issue(3)：42-48,7.DOI:10.3969/j.issn.1006-1355.2018.03.008
混合动力低地板车冷却风机降噪试验研究
Experimental Study on Noise Reduction of Cooling Fans of Hybrid Low-floor Vehicles
摘要
Abstract
Hydrogen fuel cell is used as a clean energy source in hybrid low-floor vehicles. Cooling fan is one of the key components to ensure the normal operation of the vehicles. Cooling fan noise is the dominant noise source of the hybrid low-floor vehicles whenever they are stationary or travelling at a low speed. So, diminution of vibration and noise of cooling fans is essential for the noise control of the hybrid low-floor vehicles. In this paper, the low noise design method and the efficient low noise control method are studied. Based on the experiments, the noise radiation properties of the cooling fans under different operation conditions, such as speeds, fan numbers and grid influences, and different noise-reduction schemes are studied systematically. The results show that the noise of the cooling fans is characterized by the pure tone and wide mid-frequency spectrum. The pure tone component is mainly caused by the rotational frequencies of the first three orders, and the wide-mid frequency spectrum noise is composed of the aerodynamic noise and the radiation noise of the fan-box vibration. As the fan's speed increases, the fundamental rotating frequency and the total A-weighted sound pressure level grow linearly. Under the essential prerequisite of ensuring the cooling effect, reducing the fan speed is an effective means to control the noise response. When the number of fans is halved, the radiated noise is only reduced by 2 dB(A). It indicates that the vibration of the fan-box has a significant effect on the total radiated noise. The influence of the grating on the radiated noise is very small. When removing the grate, the radiated noise is only reduced by 0.4 dB(A). The best noise reduction measures are to paste noise-reduction materials and sound-absorbing materials on bottom panels and side panels, which can reduce the noise by 2.6 dB(A). The results of the relevant test analysis have some reference value for the control of cooling fan noise and exterior noise.关键词
声学/低地板车/风机噪声/降噪/振动/声辐射Key words
acoustics/low-floor vehicle/fan noise/noise reduction/vibration/sound radiation分类
交通工程引用本文复制引用
王奇,周信,李志辉,肖新标,詹雪燕..混合动力低地板车冷却风机降噪试验研究[J].噪声与振动控制,2018,38(3):42-48,7.基金项目
国家自然科学基金资助项目(51475390) （51475390）
国家科技支撑计划资助项目(2015BAG13B01-03) （2015BAG13B01-03）
