Bubble structures and Sonoluminescence in viscous liquids
* Presenting author
Abstract:
Intense ultrasonic fields in liquids lead to acoustic cavitation, i.e. nucleation and dynamics of bubbles. Under continued sonication, the bubbles can move and form structures. Objects submerged in the liquid are attacked by collapsing bubbles, a phenomenon leading to the well-known ultrasonic cleaning, but also to surface erosion. While many applications and scientific investigations of acoustic cavitation are concerned with pure water, tap water or sea water, the behavior of acoustic bubbles in different media is less well documented. Still, type of liquid and dissolved gases are important parameters, and acoustic cavitation in oils or acids cannot be simply extrapolated from the aqueous case. Here we systematically investigate changes of bubble structures and bubble dynamics in a bath reactor when viscosity is incrementally increased from the case of pure water by adding Glycerin or Ethylene Glycol. As well, the bubble activity with respect to sonoluminescence is examined for varying viscosity.