Harmonic enhancement of single-bubble sonoluminescence.
It is known from experiment that the light emission from a sonoluminescing bubble can be increased by using more than one driving frequency. In this paper, a systematic method to determine the optimal conditions of pressure amplitude and relative phase for this effect is described. As a specific application, a two-frequency system--26.5 kHz and 53 kHz--is considered. It is found that the maximum temperatures achievable can be appreciably increased with respect to single-frequency drive, still maintaining spherical stability, provided the dissolved inert gas concentration is kept extremely low in order to maintain diffusive stability.
Lu
Xiaozhen
X
Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA.
Prosperetti
Andrea
A
Toegel
Ruediger
R
Lohse
Detlef
D