Influence of viscosity variation on the stationary Benard-Marangoni instability with a boundary slab of finite conductivity

Abstract

The onset of stationary Bernard-Marangoni instability in a variable-viscosity fluid layer with a boundary slab of finite conductivity is studied. The relations of the viscosity and surface tension of the fluid with the temperature are exponential and linear, respectively. The asymptotic solutions of the long wavelength, for small values of the conductivity and thickness of the solid, are achieved and are very well compared with the numerical results. As the viscosity ratio increases, the validity of the asymptotical solutions is extended for cases of larger values of the thermal conductivity and thickness ratios.