Collapse of a cavitation bubble between two solid walls

Abstract

A theoretical study is made of the process of cavitation bubble collapse between two solid walls in an ideal incompressible fluid. Following the method developed and running numerical calculations on an electronic computer, the radius and rate of collapse of a cavitation bubble between two solid walls have been determined for different instants of time and angles. The presence of the second solid wall, which brings about a change in the velocity and flow pattern of the added quantity of fluid, is shown to lead to a lesser rate and a markedly different scheme of collapse of cavitation bubbles. These were observed to reduce the erosive activity of acoustic cavitation due to its lesser mechanical attack on the surface and smaller heat transfer from collapsing cavitation bubbles to the surface treated as compared to the case of only one solid wall. The results obtained, when used to select the optimal conditions for surface treatment, will allow a more effective application of ultrasonic energy in those technological processes which are associated with destructive action of acoustic cavitation resulting from high pressures and heat loads.