Prediction of Cavitation Performance of Axial Flow Pump by Using Numerical Cavitating Flow Simulation with Bubble Flow Model

Abstract

The prediction of cavitation performance by using a numerical flow simulation is significant to reduce the productive cost when designing a pump impeller blade. The cavitation has several appearances in the pump such as sheet cavitation, cloud cavitation, and vortex cavitation. Cloud cavitation is composed of a lot of tiny bubbles with complex behavior. The bubble flow model is a cavitation model for numerical simulation, in which the bubble dynamics is treated in detail. In this study, we develop a new numerical simulation code that includes the bubble flow model. The code considers the distribution of the number density of bubbles, and the transitional and volumetric motions of bubbles. It was applied to a rotating flow in an axial flow pump. The predicted cavitation performance of the pump agreed qualitatively with the experiment. The predicted cavitation distribution on the impeller blade also agreed with that visualized. The code has the potential to simulate bubble behavior in cavitation erosion.