Analyses of the Characteristics of a Centrifugal Impeller with Leading Edge Cavitation by Mapping Methods

Abstract

The characteristics of a centrifugal impeller under a condition with leading edge cavitation are analyzed by using conformal mapping methods. It is assumed that the thickness of the cavity is small, and linear cavity models are used. Concerning the treatment of the Bernoulli equation, two different models are considered. The first one is based on a full Bernoulli equation in a rotating frame. In the second model, the Bernoulli equation is linearized on the assumption that the disturbance due to cavity is small. The second model predicts shorter cavity, but the differences in the pressure distribution and in the head coefficient are small for the conditions with the same cavity length. The results of the first model are in general agreement with those by a singularity method and experiments.