Numerical study on the effect of the concave rigid boundaries on the cavitation intensity

In this paper, we study the motion of a cavitation bubble near a concave boundary from a theoretical perspective. To illustrate the effect of the surface concavity of the boundary, boundary integral and finite difference methods are utilized to investigate the more detailed process of jet formation. Bubble shapes and its lifetime, movement of the bubble centroid, pressure contours, and velocity vectors are used to demonstrate the numerical results. The velocity of a liquid jet impacting on the far side of the bubble surface tends to increase with decreasing boundary concavity. This result suggests that higher pressures can occur when cavitation bubbles collapse near a concave boundary. With the increase of boundary concavity, the time evolutions of the bubble growth and collapse tend to increase, and the liquid jet is formed later. (C) 2017 Sharif University of Technology. All rights reserved.