EAGER: Experimental Investigation of Forced Convection on Hierarchical Micro/Nanoporous Conducting-Lubricating Surfaces

强制对流换热具有非常广泛的应用基础。它是影响我们日常生活的许多过程和设备所固有的，例如发电，热管理，空间运输，水净化和国防部门的热交换器和散热器。在通道/管道中的液体强制对流中，由于流动摩擦和换热性能类似地依赖于流体流速和壁面/表面特性，先前的研究人员发现，任何试图降低壁面摩擦的尝试都不可避免地导致换热速率的降低，而增加换热的努力几乎总是导致摩擦流动阻力的增加。虽然增强的传热是有益的，但壁面摩擦的增加需要更多的电力消耗，以泵送电力的形式来克服它。本提案旨在解决这一重要而艰巨的问题，在过去的几十年里，这一问题引起了很多研究的关注，即，它首次通过采用液体饱和的分层微/纳米孔表面来减少流体流动的摩擦，而对传热性能的影响可以忽略不计。重点将放在无相变液体的强制对流上。拟议的工作将对科学和社会产生更广泛的影响，这将通过新墨西哥州立大学本科和研究生阶段的课程整合和最先进的研究/课堂机会来证明。这一活动将直接有助于培养一支多元化的、具有全球竞争力的STEM劳动力队伍，他们将理解和解决国家能源利益的关键问题。为了实现项目的目标和目的，将使用一种新的蚀刻技术在流道的内部表面上制造各种粗糙度拓扑结构的坚固的分层微/纳米孔表面，并使用精确的重量测量和荧光显微镜技术对其润湿，老化和坚固性进行表征。为了验证显示该概念巨大潜力的理论预测，将在微孔/纳米孔壁面饱和的微型/微通道中进行常见冷却剂强制对流换热性能的实验研究。记录的压力、温度和流量数据将进行后处理，以获得能效指标，即在相同的泵送功率下，通过具有规则/光滑表面的相同尺寸的通道泵送相同的液体所需的增加的努塞尔数。项目的成功完成将产生新的知识基础，通过对表面亲性和鲁棒性、流动稳定性和热输运及其对表面拓扑的依赖性提供新的基本见解，从而实现强制对流输运的显著能效。

CBET-1449621Kota (New Mexico State University)Forced convection heat transfer has a very wide application base. It is inherent to numerous processes and equipment that affect our day-to-day lives such as heat exchangers and heat sinks in power generation, thermal management, space transportation, water purification and defense sectors. In forced convection of liquids in channels/pipes, due to the analogous dependence of flow friction and heat transfer performance on fluid flow velocity and wall/surface characteristics, it was found by prior researchers that any attempt to lower friction at the walls inevitably results in decreased heat transfer rate and efforts to augment heat transfer almost always result in increased frictional flow resistance. While enhanced heat transfer is beneficial, increased friction at the walls demands more electricity consumption in the form of pumping power required to overcome it. This proposal aims to resolve this important and arduous problem that has attracted much research attention in the last few decades i.e., it enables friction reduction near the walls for fluid flow but for the first time, with negligible impact on heat transfer performance by employing liquid-saturated hierarchical micro/nanoporous surfaces. The focus will be on forced convection of liquids without phase change. The proposed work has broader impacts on science and society, which will be demonstrated through curriculum integration and state-of-the-art research/classroom opportunities at the undergraduate and graduate levels at the New Mexico State University. This activity will directly help in developing a diverse, globally competitive STEM workforce that would understand and address critical issues of national interest in energy.For achieving the project goals and objectives, robust hierarchical micro/nanoporous surfaces of various roughness topologies will be fabricated on internal surfaces of flow channels using a novel etching technique, and their wetting, aging, and robustness aspects will be characterized using precise weight measurement and fluorescence microscopy techniques. To verify the theoretical predictions that showed substantial potential of the concept, experimental investigation of forced convective heat transfer performance of common coolants will be carried out in mini/microchannels with water saturating the micro/nanoporous wall surfaces. The recorded data of pressures, temperatures and flow rates will be post-processed to obtain an energy-efficiency metric, which will be the increased Nusselt number for the same pumping power required to pump the same liquid through a same sized channel with regular/smooth surfaces. Outcomes as a result of successful completion of the project will generate new knowledge base for realizing significant energy efficiencies in forced convective transport by providing novel fundamental insights on surface -philicity and robustness, flow stability and thermal transport, and their dependence on surface topology.