The broadband noise sources are investigated on an isolated low-speed fan typical of engine cooling systems. Reynolds-averaged Navier-Stokes (RANS) simulations have been performed on a single blade passage for several flow rates at the same rotational speed. The flow structures responsible for the different noise contributions are identified by a systematic analysis of the simulation results.
View Article and Find Full Text PDFA joint experimental and numerical study has been achieved on a low-speed axial ring fan in clean inflow. Experimental evidence shows large periodic broadband humps at lower frequencies than the blade passing frequencies and harmonics even at design conditions. These sub-harmonic humps are also found to be sensitive to the fan process and consequently to its tip geometry.
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