269 Mechanism of Noise Generation in a Wing Profile Centrifugal Blower : Search for Turbulent Noise Source with Flow Visualization

Abstract

The present study intended that search for turbulent flow noise source in a wing profile centrifugal blower. First, we examined velocity and direction of flow with flow visualization of blade around. These brought out large change in flow in blade trailing edge of impeller center. At best efficiency point, it becomes small. Next, fluctuating pressure in blade trailing edge was measured with probe microphone. These brought out turbulent flow element of sound pressure level that was high from impeller center to lateral plate side.