Thermo-solutal convection with soret effect

热扩散现象，也称为热扩散或索雷特效应（在液体中），描述了在多组分系统中温度梯度和由此产生的质量通量之间的耦合。当气体中的热扩散被广泛研究并被动力学理论很好地解释时，近年来液体中的热扩散也引起了越来越多的科学和工程兴趣。例如，热扩散被认为是油藏成分分布分析不可或缺的一部分。一些研究人员推测，生物大分子的热扩散可能在生命的起源中发挥了作用。本研究首先利用流动溶剂法（TSM）对硅锗（Silicon Germanium, SiGe）材料生长过程中的溶质热对流进行持续研究。其次，进一步扩展了非均匀多孔腔内热扩散对流的研究。相对于前一部分所提出的研究，TSM是一种相对较新的、有前途的高质量半导体材料生产技术。获得高纯度SiGe半导体材料是光电探测器和太阳能电池生产的关键方面。我们建议使用磁场来抑制浮力对流，从而允许对Si/SiGe系统中的热扩散进行详细研究。所得的数值/理论结果将与达尔豪斯大学正在进行的实验研究进行比较。对于拟建研究的后半部分，研究将扩展到高压下填充不同二元烃混合物的非均匀多孔介质中的流体流动、传热和传质。不同混合物的分子和热扩散系数将作为有限元网格上每个点的温度和浓度的函数来估计。然后将数值计算结果与目前法国波大学的实验装置进行比较。

The thermodiffusion phenomenon, also known as thermal diffusion or the Soret effect (in liquids), describes the coupling between a temperature gradient and the resulting mass flux in a multi-component system. While thermodiffusion in gases is being widely investigated and is well explained by the kinetic theory, thermodiffusion in liquids has also given rise to increasing scientific and engineering interest in recent years. For example, it has been postulated that thermodiffusion is integral to the analysis of the composition distribution in oil reservoirs. Some researchers have speculated that the thermodiffusion of biomacromolecules may play a role in the origin of life. The proposed research firstly focuses on the continual investigation of solutal thermal convection during the growth process of Silicon Germanium (SiGe) material using the Travelling Solvent Method (TSM). Secondly, the research aims to further extend the study of thermodiffusion convection in an inhomogeneous porous cavity. With respect to the former portion of the proposed research, TSM is a relatively new and promising technique for the production of high quality semiconductor materials. Achieving high purity SiGe semiconductor material is a pivotal aspect of the production of photodetectors and solar cells. We propose to use magnetic fields in order to suppress buoyancy convection, thus allowing for a detailed study of thermodiffusion in Si/SiGe system. The obtained numerical/theoretical results will be compared with undergoing experimental research at Dalhousie University. With respect to the latter part of the proposed research, the investigation will be extended to study fluid flow, heat and mass transfer in inhomogeneous porous media filled with different binary hydrocarbon mixtures at high pressure. The molecular and thermodiffusion coefficients for different mixtures will be estimated as function of the temperature and concentration at each point of the finite element grid. Then the numerical results will be compared with the experimental setup that is currently at the Universite de Pau in France.