Experimental Prediction Methodology of Broadband Noise Generated from a Cooling Fan

Abstract

The experimental prediction methodology of the broadband noise for a low-pressure cooling fan by the blade element momentum theory is proposed. For the prediction equation of the broadband noise, the theory on the acoustic radiation from airfoil with turbulent boundary layer is applied. The broadband noise of the fan is predicted experimentally by using the measured flow regime in the near wake of the actual fan based on the results of the wind tunnel test on the aerodynamic noise of a flat plate. The prediction by the suggested methodology could explain the reduction of the broadband noise in the low frequency domain in the operation point of the cooling fan is the effect of the reduction of the wake vortex noise made by the pressure side separation.