Direct numerical simulation of the mechanism of surface tension auto-oscillation

Abstract

A theoretical investigation of the surface tension auto-oscillations is performed by direct numerical simulation of the behaviour of a system where a surfactant droplet dissolves under the free water surface. The chosen model allows for the geometry of the measuring cell. The Marangoni effect is accepted as responsible for giving rise to the instability. The simulation shows that the system behaviour to prior the first oscillation does not depend on the radial dimension of the system. The development of a second and following oscillations is only possible in systems with limited dimensions. The calculated dependence of the surface tension on time is in good agreement with the experimental results.

Acknowledgements. N.M.K. thanks gratefully the Max-Planck Gesellschaft for financial support.