EFFECT OF VORTICITY DISTRIBUTION ON THE BLADES ON FAN NOISE

Abstract

Tests have been performed to determine the connection between noise emission of radial flow fans, impellers, with different inlet design, and vorticity distribution on the blades. An inlet cone protruding into the impeller was found to reduce significantly the radiated sound power level. Measurements showed that for the tested impellers about the duty point corresponding to maximum efficiency, vorticity distribution on the blades has little effect on the sound power level.