564 Reduction of Noise in a Wing Profile Centrifugal Blower : Flow and Pressure Fluctuation in the Vicinity of Cut-off

Abstract

The present study intended that clarification of generating mechanism of blade passing frequency (BPF) noise in wing profile centrifugal blower. First, flow in the vicinity of cut-off in generation source of BPF noise visualized brought out relation between blade passing and flow. Next, probe microphone measured fluctuating pressure source of BPF noise in cut-off surface. Distribution of fluctuating pressure pinpointed major source of BPF noise. Measurement of wind position just as fluctuating pressure brought out relation between blade passing and fluctuating pressure.