Cloud cavitation dynamics

Abstract

An analysis is developed for the behaviour of a cloud of cavitation bubbles during both the growth and collapse phases. The theory is based on a multipole method exploiting a modified variational principle developed by Miles for water waves. Calculations record that bubbles grow approximately spherically, but a staggered collapse ensues with the outermost bubbles in the cloud collapsing first of all, thence leading to a cascade of bubble collapses with very high pressures developed near the cloud centroid. A more complex phenomenon occurs for bubbles of variable radius with local zones of collapse, with a complex frequency spectrum associated with each individual bubble, leading to both local and global collective behaviour. doi:10.1017/S1446181109000133