Single-phase liquid flow in minichannels and microchannels
Single-phase liquid flow in minichannels and microchannels
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DOI：
10.1016/b978-0-08-098346-2.00003-x
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
S. Kandlikar
中科院分区：
文献类型：
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作者：
S. Kandlikar
微通道用于多种结合单相液体流的装置。早期的应用涉及微机械设备，例如微型泵、微型阀门和微型传感器。随之而来的是生物和生命科学的发展，需要分析生物材料，如蛋白质、DNA、细胞、胚胎和化学试剂。随着微反应器的发展，微混合器领域进一步受到关注，微反应器将两种化学物质在引入反应室之前进行混合。高速微处理器的高通量散热为微通道传热的研究提供了动力。微机电设备的发展自然需要同样小的排热系统。高功率激光系统中使用的反射镜的冷却涉及占地面积非常小的冷却系统。生物医学和基因工程的进步需要受控的流体传输及其在几微米尺寸的通道中的精确热控制。因此，正确理解这些微尺度系统中的流体流动和传热对于它们的设计和操作至关重要。在没有任何壁面效应（例如第 4 章中介绍的电动或电渗力）的情况下处理微型通道和微通道中的液体流动时，预计流动不会经历与宏观流体应用中使用的连续介质近似相比的任何根本变化。 Gad-el-Hak (1999) 认为水等液体应被视为连续介质，并得出结果
Microchannels are used in a variety of devices incorporating single-phase liquid flow. The early applications involved micromachined devices such as micropumps, microvalves, and microsensors. This was followed by a thrust in the biological and life sciences with a need for analyzing biological materials, such as proteins, DNA, cells, embryos, and chemical reagents. The field of micromixers further received attention with developments in microreactors, where two chemical species are mixed prior to introducing them into a reaction chamber. The high flux heat dissipation from high-speed microprocessors provided the impetus for studies on heat transfer in microchannels. The developments in the microelectromechanical devices naturally require heat removal systems that are equally small. Cooling of mirrors employed in high-power laser systems involves cooling systems that cover very small footprints. Advances in biomedical and genetic engineering require controlled fluid transport and its precise thermal control in passages of several micrometer dimensions. A proper understanding of fluid flow and heat transfer in these microscale systems is therefore essential for their design and operation.In dealing with liquid flows in minichannels and microchannels in the absence of any wall surface effects, such as the electrokinetic or electroosmotic forces that are covered in Chapter 4, the flow is not expected to experience any fundamental changes from the continuum approximation employed in macrofluidic applications. Gad-el-Hak (1999) argued that liquids such as water should be treated as continuous media with the results obtained