Thermo-hydraulic instability of liquid-vapour interface in porous media

多孔介质中的液-气相变在工程应用中起着重要的作用。虽然在过去已经取得了重大进展，相变现象的一些元素没有得到很好的理解，尽管多年的广泛研究。目前需要进一步研究的领域之一是毛细驱动流的液-汽界面不稳定性。界面不稳定性通过改变相变过程，可导致传热设备的性能异常和机械损坏。拟议的研究项目旨在通过实验和数值研究来研究多孔介质中液-汽相变过程中遇到的热工水力不稳定性。该项目的主要目标之一是扩展先前开发的数学模型，以便能够提出设计改进以消除或补救性能异常。更好地理解这些不稳定性的潜在物理机制对于一些技术应用（燃料电池，核反应堆，能量转移，化学处理等）非常重要。越来越重要的一个重要应用领域是两相毛细泵送传热装置。这些装置用于转移计算机中的微处理器或航天器中的电子仪器等发热部件的多余热量，同时将温度保持在指定范围内。与传统的冷却技术相比，这些设备的优点包括简单、没有移动部件以及能够长距离传递大量热量。在没有更好的数学模型的情况下，这项技术的进步仍然很困难。

The liquid-vapour phase change in porous media plays a vital role in a wide variety of engineering applications. Although significant progress has been made in the past, some elements of phase-change phenomena are not well understood despite many years of extensive research. One of the areas where there is currently a need for further research is liquid-vapour interface instabilities of the capillary-driven flows. The interface instabilities can lead to performance anomalies and mechanical damage of heat transfer equipment by altering the phase-change process. The proposed research project aims to study thermo-hydraulic instabilities encountered during the liquid-vapour phase change process in porous media through experimental and numerical investigation. One of the main goals of the project is to expand a previously developed mathematical model to be able to suggest design improvements to eliminate or remedy the performance anomalies.A better understanding of the underlying physical mechanisms of these instabilities would be of great importance for several technological applications (fuel cells, nuclear reactors, energy transfer, chemical processing, etc.). An important application area of growing importance is two-phase capillary-pumped heat transfer devices. These devices are used to transfer excess heat from a heat-producing component such as a microprocessor in a computer or an electronic instrument in a spacecraft, while maintaining the temperature within a specified range. The advantages of these devices over conventional cooling techniques include simplicity, lack of moving parts, and the ability to transfer large amounts of heat over long distances. In the absence of better mathematical models, advancement in this technology will remain difficult.