Ultrasonics, 3rd Edition

11    Applications of High-Intensity Ultrasonics

Basic Mechanisms and Effects

11.1    INTRODUCTION

High-intensity applications of ultrasonics are those that produce changes in or effects on the media, or the contents of the media, through which the waves propagate. Various mechanisms may be activated by the ultrasonic energy to promote the effects, but the mechanisms involved are not always well known or understood. The phenomena that occur with high-intensity ultrasound interactions are in most cases nonlinear [1]. The complexity of these phenomena can best be illustrated with an example: energy is concentrated and transformed in cavitation. In cavitational collapse, temperatures of more than 5000 K and pressures greater than 50 MPa (above ...