Asymmetric Flow in Vaneless Diffusers of Centrifugal Blowers

Abstract

An analytical method is proposed to evaluate the flow behavior in vaneless diffusers assuming that the flow is not symmetric between the walls. In the analysis momentum integral equations are used together with some special relations for the main flow or for the maximum velocity flow. According to the authors’ experiment, for the case of a small flow rate a reverse flow is observed on one wall near the inlet of the diffuser but at a larger radius the reverse flow disappears and another reverse flow is observed on the other wall. The predictions quantitatively agree well with experiments not only in the case of large flow rates but also in the case of small flow rates where the flow pattern is very complicated.