两层液体Bénard-Marangoni对流的界面张力效应

Interface tension effect in two-layer Bénard-Marangoni convection

采用PIV技术对两层流体Bénard-Marangoni对流进行了实验研究,得到了不同厚度比下的速度场,分析了界面张力在各种对流模式中的作用。和Rayleig-Bénard对流的三种临界对流模式相比,由于界面张力对上下层浮力对流的不同作用效果,使得更复杂的临界对流模式在Bénard-Marangoni对流体系中出现;在实验中首次观测到三层涡胞结构等现象。

In this paper, the problem of Benard-Marangoni convection in the two-layer 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-Brnard convection of two-layer fluid, more complex phenomena are induced by the interfacial tension in the Benard-Marangoni convection in the twolayer fluid. Meanwhile the flow structure of the three-layer vortices is also observed.