Thermal noise and the stability of single sonoluminescing bubbles
The stability of a bubble levitated in an acoustic field under single bubble sonoluminescence conditions was numerically investigated taking thermal noise effects into consideration. Due to the microscopic size of a sonoluminescing bubble thermal noise is important to its surface and is found to cause small irregularities in its spherical shape. A stochastic differential equation in Langevin form is derived to describe the dynamics of a perturbation from the spherical and solved together with the Rayleigh-Plesset equation. The mechanisms responsible for the amplification of small irregularities are examined and a stability threshold is derived, which is in good agreement with experimental threshold data of Holt and Gaitan.
Augsdorfer
UH
Faculty of Computing Science and Engineering, Department of Mathematical Sciences, De Montfort University, Leicester, England. uha@dmu.ac.uk
Evans
AK
Oxley
DP