Azimuthal Mode Experiment of Aerodynamic Noise of Axial Flow Fan for Electronic Device Heat Dissipation

doi:10.3901/JME.2020.18.164

Abstract

Abstract: The azimuthal acoustic mode of the axial cooling fan with imported irregular shapes for electronic device is not clear yet, thus a deeper understanding of its noise characteristics is needed. An experimental study on the aerodynamic noise characteristics of a variable-speed axial flow fan commonly used in the field of electronic device heat dissipation is conducted. First, the far-field noise spectrum characteristics and directivity of the fan are analyzed. The amplitude of 1st order blade passing frequency is the largest on the inlet side while the largest is 3rd order blade passing frequency on the outlet side, indicating there are different influence factors of discrete single tones on the either side. It is found that the setting of the motor wire on the strut has a significant influence on the total sound pressure level and noise directivity. Afterwards, based on the mode correction method utilizing 18 and 8 uniform sampling points, the azimuthal acoustic mode distributions at 1st-3rd order blade passing frequencies on the inlet and outlet sides of the axial flow cooling fan are accurately identified. Considering the non-axisymmetric shape of the fan inlet shroud, the traditional TYLERSOFRIN rotor-stator interaction formula is modified and its effectiveness is verified by experiments.

Key words: cooling fan, noise spectrum, directivity, mode identification

CLC Number:

TH42

SUN Zonghan, TIAN Jie, ZHENG Haoxuan, YU Zean, OUYANG Hua. Azimuthal Mode Experiment of Aerodynamic Noise of Axial Flow Fan for Electronic Device Heat Dissipation[J]. Journal of Mechanical Engineering, 2020, 56(18): 164-171.

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