Heat pipe design optimization through the application of surface chemical treatments and the adaptation of core annular flow theory

在一定距离内快速有效地传递热量的能力对于许多工程行业至关重要，例如航空航天，电子和暖通空调。完成这项任务的一个特别有效的装置是热管，其最简单的形式是由一个封闭的金属管组成，其中有一种工作流体，分别在管道热和冷的地方蒸发和凝结。我们将与一家致力于制造新型传热和空气处理设备的加拿大公司合作，利用表面科学和微流体学的新进展，更好地了解热管的操作，以期通过更好的设计提高性能。除了产生新的知识和训练各种各样的学生，我们的主要（工业）交付将是一个能够通知设计决策的计算机程序。该项目将利用该领域40年的原始研究成果，也将利用我们实验室项目产生的新成果。更具体地说，我们计划通过实验测试使用表面化学处理来改变芯的表面能的可行性，芯是热管内部的组件，被动地将冷凝液体“泵”回热管的热端。通过这样的化学处理，我们希望实现有利的蒸发和冷凝制度，并分别减少夹带，通过这个过程，液滴被剪离灯芯。在相关的理论工作中，我们计划采用核心环流理论的思想，以改进液-汽逆流的动力学描述。我们的研究结果将在科学文献中进行交流，并由工业合作伙伴进行实际应用。在后一个方面，我们设想通过提高设计能力和加拿大公司渴望新机会的盈利能力来做出关键的技术贡献。

The ability to transfer heat quickly and efficiently across modest distances is essential to many engineering industries e.g. aerospace, electronics and HVAC. An especially effective device for accomplishing this task is the heat pipe, which, in its simplest incarnation, consists of a closed metal tube inside of which is a working fluid that respectively evaporates and condenses where the tube is hot and cold.Working with a Canadian company committed to fabricating novel heat transfer and air handling equipment, we will use new advances in surface science and micro-fluidics to better understand heat pipe operation with a view towards improving performance through better design. In addition to generating new knowledge and training a variety of students, our major (industrial) deliverable will be a computer program capable of informing design decisions. The program in question will leverage four decades of original research in the field and will also make use of new results generated through our laboratory program. More specifically, we plan to experimentally test the feasibility of using surface chemical treatments to modify the surface energy of the wick, the component internal to the heat pipe that passively "pumps" condensed liquid back to the hot end of the heat pipe. Through such a chemical treatment, we hope to realize favourable regimes of evaporation and condensation and to separately minimize entrainment, the process by which liquid droplets are sheared away from the wick. In a related theoretical effort, we plan to adapt ideas from core annular flow theory so as to improve the dynamical description of the liquid-vapour counterflow.Results from our study will be both communicated in the scientific literature and also adapted for pragmatic application by the industrial partner. In this latter respect, we envision making a key technical contribution by improving the design capabilities and also the profitability of a Canadian company eager for new opportunities.