Experimental Study of Noise and Aerodynamics for Dual Cascades Centrifugal Fan : Effects of the Inlet/Outlet Area Ratio of the Impeller

Abstract

The impeller of dual cascades centrifugal fan consists of two cascades which are arranged in the span direction. The inner diameter, chord length and the number of blades are different between two cascades. In this experiment, the span of both cascades are varied with keeping the total span constant. Then the influences of the inlet/outlet area ratio of both cascades to the fan noise and the aerodynamics are researched. The fan noise level of the dual cascades cetrifugal fan is lower than that of the single cascade fan, and the aerodynamic performances of the former is almost the same to the latter at the maximum efficiency point.