REU Supplement: Mesoscale Heat Exchangers

该项目是对非常小的通道中的传热过程的研究，目标是开发高度紧凑，高性能的热交换器（传热率在105W/m2K左右，是可行的）。微电子工业发展的微加工技术允许在硅或其他合适的材料上制造小尺寸、高精度的通道。拟议的通道尺寸将在宽度和深度上从几微米到几分之一毫米不等。在研究的初始阶段，拟议的通道长度将被限制在大约1-2厘米。在极小的体积中可以容纳大量的通道。平面光刻技术为制造极其复杂的翅片和扩展面提供了一种适合优化传热过程的方法。所建议的热交换器应能够在两种流体之间或从单一流体到环境中提供有效的热传递。除了效率之外，所提出的热交换器的其他优点是它们的质量非常小，工作液体库存少，支撑结构小，成本低，无振动。这种类型的热交换器代表了一类热元件，这些热元件以前没有在这里考虑的尺寸范围内进行过研究，这表明从纯科学的角度来看，对这种中尺度范围内的热交换进行基本研究是可取的。拟议的研究本质上是跨学科的，因为它同时解决了传热、材料、监测传热过程的传感器元件和微加工问题。

This project is an investigation of heat transfer processes in very small channels with the goal of developing highly compact, high performance heat exchangers (heat transfer rates on the order of 105W/m2K, are feasible). Microfabrication techniques developed in the micro-electronic industry permit the fabrication of small size, high precision channels in silicon or other suitable materials. The proposed dimensions of the channels will range from a few microns to fractions of a millimeter in width and depth. The proposed lengths of the channel will be restricted to approximately 1-2 centimeters in the initial stages of the study. Large numbers of channels can be accommodated in extremely small volumes. Planar photolithographic technology provides a method for fabricating extremely complicated fins and extended surfaces suited to optimizing the heat transfer process. The proposed heat exchangers should be able to provide efficient heat transmission between two fluids or from a single fluid to the ambient. Other advantages of the proposed heat exchangers, aside from efficiency, are their very small mass, low inventory of working liquids, small supporting structures, low cost, and vibration-free character. This type of heat exchanger represents a class of thermal elements that have not been previously studied in the dimensional regime being considered here, suggesting that a fundamental inquiry into heat exchange in this mesoscale regime is desirable from a purely scientific viewpoint. The proposed research is interdisciplinary in nature as it addresses simultaneously heat transfer, materials, sensor elements for monitoring the heat transfer processes, and microfabrication issues.