Correction of Lift Coefficient for Tandem-Circular-Cascade Diffusers

Abstract

In order to predict the performance of a high-staggered low-solidity tandem circular-cascade diffuser of a centrifugal blower, variation of the lift-coefficient due to the mutual interaction between the two cascades is numerically evaluated assuming an inviscid flow. A tandem circular-cascade diffuser is tested at two different circumferential relative positions and the significant influence of the relative position on the lift coefficient is demonstrated. The blade circulation of each cascade is also evaluated from the measured pressure distribution along the blade surface and good agreement with the prediction is demonstrated.