Acoustic Cavitation Measurements and Modeling in Liquid Aluminum

Abstract

The quantification of acoustic pressures in liquid metals is of paramount interest for the optimization of ultrasonic melt treatment (UST) of large volumes. Until recently, the measurements of acoustic pressure and cavitation intensity in a melt were cumbersome and unreliable due to the high temperatures and the lack of suitable instruments. These difficulties imposed strict limitations on the experimental and numerical investigation of cavitation and bubble dynamics within liquid metals. In recent years, our group used a unique calibrated high temperature cavitometer to measure cavitation activity and acoustic pressures in liquid aluminum. Phenomena such as acoustic attenuation, shielding, and cavitation intensity have been studied. These measurements were also used to validate a non-linear acoustic numerical model applicable to flow in bubbly liquids subject to acoustic cavitation. Both experimental and numerical characterization of the acoustic and flow fields provides a powerful tool to optimize cavitation processing in liquid metals.