Prediction of cavitation intensity and erosion area in centrifugal pump by using cavitating flow simulation with bubble flow model

Abstract

We developed a numerical simulation code and an estimation method for predicting the cavitation erosion in pumps. The cavitation erosion is closely related to the cavitation intensity based on the bubble dynamics. A 'bubble flow model' simulates the detailed bubble behavior in a cavitating flow. The cavitation intensity was estimated by analyzing the bubble pressure and the bubble nuclei distribution in a centrifugal pump. We simulated impulsive bubble pressure that varied in microseconds. The impulsive pressure is considered to be related to actual bubble collapse, which causes the cavitation erosion. The erosion area was experimentally detected using a paint method. The predicted high cavitation intensity area agreed well with the experimental erosion area, since the predicted and experimental areas were both located between the shroud and mid-point of the blade near the leading edge. Our code is thus effective for estimating the cavitation intensity and predicting the erosion area around the impeller of a centrifugal pump.