电子器件散热串联轴流风扇短管降噪试验

对两台电子器件散热轴流风扇采用不同方式串联时的气动噪声特性开展试验研究。首先利用风扇等高平面内环形布置的传声器阵列对单风扇和串联风扇的远场噪声进行测量,发现串联风扇相比单风扇具有更高的宽频噪声和更复杂的单音噪声特性。然后对比加装方框、蜂窝和短管中间连接件的串联风扇在不同转速下的噪声声压级指向性分布,发现短管连接件对串联风扇的单音和宽频噪声均具有良好的降噪效果,其中设计转速下单音相比方框连接的串联风扇下降1.2dB(A),宽频下降0.5dB(A)。最后,提出串联风扇的两段短管降噪方法并验证了其在多转速运行工况下的降噪效果。论文对串联电子器件散热风扇气动噪声的研究可为工程应用中的降噪措施提供参考。

Experimental Study on Aerodynamic Noise Reduction of In-series Axial Cooling Fans for Electronic Devices

An experimental study on the aerodynamic noise characteristics of two electronic device axial flow cooling fans connected in series in different ways is carried out. First, the far-field noise of a single fan and fans in series is measured by a microphone array arranged in a ring in the contour plane of the fan. It is found that fans in series had higher broadband noise and more complex tonal noise than the single fan. Then the directivity of the sound pressure level of fans in series with middle connectors of the square,honeycomb and short duct at different rotational speeds is compared. The connector of short duct had a good noise reduction effect on the tonal and broadband noise of fans in series, in which the tonal noise decreased 1.2 dB(A) and the broadband noise decreased 0.5dB(A) compared with the square connected fans at the rated speed. Finally, the noise reduction method of two-stage short duct for fans in series is proposed and its noise reduction effect at multi-speed is verified. The research on the aerodynamic noise of axial flow cooling fans in series can provide reference for the noise reduction measures in the engineering application.