Thermo-solutal convection with soret effect

热扩散现象，也称为热扩散或Soret效应(在液体中)，描述了多组分体系中温度梯度和由此产生的质量通量之间的耦合。近年来，气体中的热扩散得到了广泛的研究，并被动力学理论很好地解释，而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，人们假设热扩散是分析油藏中组分分布所不可或缺的。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(SiGe)材料生长过程中的溶质热对流进行了连续研究。其次，本研究旨在进一步拓展非均匀多孔空腔内热扩散对流的研究。与前一部分研究相比，TSM是生产高质量半导体材料的一种相对较新和很有前途的技术。获得高纯度的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，从而对Si/SiGe系统中的热扩散进行详细的研究。所获得的数值/理论结果将与达尔豪西大学正在进行的实验研究进行比较。在研究的后半部分，研究将扩展到高压下充填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。不同混合物的分子扩散系数和热扩散系数将被估计为有限元网格上每个点的温度和浓度的函数。然后将数值结果与目前在法国保罗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.