Interface tension effect in two-layer Bénard-Marangoni convection

In this paper,the problem of Benard-Marangoni convection in the twolayer fluid near onset is investigated with PIV method.The measurement of the velocity fields for different depth ratio display many convective patterns.The analysis of the results indicates the interface tension plays an important role in the Benard-Marangoni convection of two-layer fluid.Comparing with the Rayleigh-Benard convection of two-layer fluid,more complex phenomena are induced by the interfacial tension in the Benard-Marangoni convection in the two-layer fluid.Meanwhile the flow structure of the three-layer vortices is also observed.