Thermal Convection in an Annular Two-Layer System Under Combined Action of Buoyancy and Thermocapillary Forces
Thermal Convection in an Annular Two-Layer System Under Combined Action of Buoyancy and Thermocapillary Forces
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DOI：
10.1007/s10948-010-0681-4
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发表时间：
2010-01
影响因子：
1.8
通讯作者：
You-Rong Li;Wen-jie Zhang;L. Peng;Shuang-Ying Wu
中科院分区：
文献类型：
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作者：
You-Rong Li;Wen-jie Zhang;L. Peng;Shuang-Ying Wu
采用有限体积法对具有不可变形界面的两个不相容液层在外加热圆筒和内冷却圆筒环形空腔内的对流换热进行了二维数值模拟。底面和顶面由两面坚硬的隔热墙包围。结果表明，热对流的转换依赖于环形空腔的Marangoni数、长宽比和曲率。对于足够小的Marangoni数，流动是稳定的，并且每个流体层中都有一个单元。当Marangoni数超过临界值时，对流变得不稳定，并产生非定常的多单体结构。在封闭环形空腔的情况下，临界Marangoni数的值大于无限大层的临界Marangoni数，并随长宽比的增大而减小。
A set of two-dimensional numerical simulations of thermal convection of two immiscible liquid layers with a non-deformable interface was carried out in an annular cavity with the outer heated cylinder and the inner cooled cylinder using the finite-volume method. Bottom and top surfaces were bounded by two rigid and heat-insulated walls. The results show that the conversion of the thermal convection depends on the Marangoni number, the aspect ratio and the curvature of the annular cavity. For a sufficiently small Marangoni number, the flow is steady and there is one cell in each fluid layer. When the Marangoni number exceeds the critical value, the convective flow becomes instable and generates an unsteady multi-cell structure. In the case of the closed annular cavity, the value of the critical Marangoni number is higher than that in the infinite layer, and decreases with the increase of the aspect ratio.