Instability of Two-Layer Rayleigh-Bénard Convection with Interfacial Thermocapillary Effect

The linear instability analysis of the Rayleigh-Marangoni-Bénard convection in a two-layer system of silicon oil 10 cS and fluorinert FC70 liquids are performed in a larger range of two-layer depth ratios H_r from 0.2 to 5.0 for different total depth H ≤ 12 mm. Our results are different from the previous study on the Rayleigh-Bénard instability and show strong effects of thermocapillary force at the interface on the time-dependent oscillations arising from the onset of instability convection.