Performance of Straight-Through Type Labyrinth Seal for a Low-Pressure Axial Flow Fan with Outer Ring

Abstract

The low-pressure axial flow fans with an outer ring, used for cooling automobile radiators, have a significantly large tip clearance between the ring tip and the fan shroud. It has been known that the turbulence of reverse flow, or leakage flow, which occurs at the tip clearance, greatly affects the performance and noise level. In order to improve the performance and noise level, the authors studied about the labyrinth seal which was used at the clearance. As a result, we discovered that it was possible to predict the performance by conventional theory when the labyrinth was stationary, and that the leakage rate decreased significantly even though the ring speed was much less than that of past research when the ring was rotated.