G0501002 Flow Oscillation Occuring in an Impeller with Forward-Inclined Multi-Blades

Abstract

The experimental and numerical studies were performed to clarify the fundamental flow characteristics of a fan with forward-inclined multi-blades. A Sirocco fan and crossflow fan are rotated in the open space, i.e. without casing. The crossflow fan simulates a Sirocco fan with a closed inlet. Using fan's height is 115mm, the inlet and outlet radii are 160 and 180 mm, respectively. The inlet and outlet blade angles are 90 and 150 degrees, respectively. The impller includes 52 blades. The rotational frequency is set to 24 Hz. The radial velocity fluctuations at the impeller outlet are measured using a hot-wire anemometry. The experimental and numerical results show good agreements with respect to frequencies and cell numbers. The FFT spectra of the experimental and numerical results show two peaks in the Sirocco fan and one peak in the crossflow fan. The two- and three-cell oscillations occur for the Sirocco fan, and the one-cell for the crossflow fan.