Noise-reduction mechanism for multi-factor coupling bionic design and the influence on aerodynamic performance and noise of multi-blade centrifugal fan are numerically and experimentally investigated. The noise-reduction characteristics of the leading edge and trailing edge structures of the goshawk wing are extracted
and multi-factor coupling bionic blade with the serrated trailing edge and non-smooth leading edge is designed by reverse reconstruction. The large eddy simulation coupled with the wall-adapting local eddy-viscosity model and the Ffowcs Williams-Hawkings equation are solved to simulate the flow field and the sound field of the bionic blade. By analyzing the flow characteristics
noise reduction mechanism of bionic blade is revealed. The serrated trailing edge structure alters the vortex shedding structure of the bionic blade to reduce the continuity and the shedding frequency
while the non-smooth leading structure effectively suppresses pressure fluctuation on blade surfaces and weakens airflow impact to leading edge of the bionic blade. Compared with the original blade
both the fundamental frequency and frequency multiplication of the bionic blade are reduced. A-weighted sound pressure level decreases by 2.1 dB. Six kinds of blade are applied to a multi-blade centrifugal fan
the effects of the blades with different structure parameters on the performance and noise are experimentally studied. It is found that the maximum noise of the multi-blade centrifugal fan decreases by 1.5 dB but the flow rate and pressure remain unchanged.
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