Experimental Study for the Effect of Vaned Diffuser Leading Edge on the Noise Generated From a Centrifugal Fan

This paper studies a novel vaned diffuser with inclined leading edge to reduce the fan noise. The aerodynamic performances and sound pressure level (SPL) of the centrifugal fan with five different diffusers were measured in an anechoic chamber, and the inclined angles of the five diffusers are 45°, 60°, 120°, 135° and 150°, respectively. The flow coefficient of the fan varies from 0.037 to 0.14, the rotational speed ranges from 20000rpm to 35000rpm. The test results show that, by using diffuser vanes with inclined leading edge, the overall noise of the fan is reduced in the experimental conditions, and it has the minimum value at the flow rate coefficient of 0.084. The overall noise reduction of 5.3dB was made with the diffuser leading edge inclined angle of 150°.