Interfacial Driven Convection - The Effect of Side Walls on Pattern Development

摘要/ ABSTRACT摘要：本文拟研究的重点是堆积流体层中界面驱动对流。一个特定的目标是研究侧壁对叠加流体的流动模式或结构的影响。PI期望找到以下内容：a)有界两层系统中对流开始的条件，并将我们的结果与计算结果进行比较；b)双层系统开始后区域的流型发展；c)三层系统的开始条件，其物理性质与两层系统有很大不同。实验将在圆形和矩形圆柱形容器中进行，多层将在垂直方向上被两块水平导热板包围，其中一块是透明的。启动的临界条件将由传热和流动可视化的增强来确定。一个施密特-米尔弗顿式的地块将被制作出来。详细的对流流动模型将与实验结果进行比较。由于界面驱动或Marangoni-B - nard对流的多层相互作用，该问题具有丰富的物理意义。这种相互作用与界面上的热量和动量传递有关。甚至几何变化也会影响界面的相对重要性。这个问题也是液体封装晶体生长的一个重要原型，在提案中对此进行了解释。PI期望这项研究将回答与多层相互作用、几何变量、性质和加热方向有关的对流不稳定性的一些重要问题。这些问题包括重力效应的作用以及浮力和界面张力梯度诱导对流之间可能的对抗机制。振荡的产生和该区域热传递的增强的有趣方面将影响到封装晶体生长问题的应用。

ABSTRACT -- CTS-9307819 Narayanan The proposed research focuses on interfacial driven convection in stacked fluid layers. A specific goal is the study of the effect of sidewalls on the flow pattern or structure in superposed fluids. The PI expects to find the following: a) the conditions for the onset of convection in a bounded two layer system and compare our results to calculations, b) the flow pattern development in the post onset region for a bi-layer system, c) the onset conditions in a tri-layer where the physics are considerably different than a two layer system. An experiment will be conducted in circular and rectangular cylindrical containers and the multi-layer will be bounded in the vertical direction by two horizontal thermally conducting plates, one of which is transparent. The critical conditions for onset will be determined by the enhancement of heat transfer and flow visualization. A Schmidt-Milverton type of plot will be made. A detailed model of the convective flow will be compared with the experimental results. This problem is rich in physics on account of multi-layer interaction in interfacial driven or Marangoni-B nard convection. This interaction is connected to the heat and momentum transfer at the interface. Even geometric changes affect the relative importance that the interface plays. This problem is also an important prototype of liquid encapsulated crystal growth and this is explained in the proposal. The PI expects that this study will answer some important questions on convective instability as related to multi-layer interaction, geometric variables, properties and heating direction. Such issues include the role of gravitational effects and a possible counter mechanism between buoyancy and interfacial tension gradient induced convection. The interesting aspect of generation of oscillations and the enhancement of heat transfer in this region will affect application to the problem of encapsulated crystal growth.