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

EAGER：分级微/纳米多孔导电润滑表面强制对流的实验研究

• 批准号: 1449621
• 负责人: Krishna Kota
• 金额: $ 5.52万
• 依托单位: New Mexico State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1449621&HistoricalAwards=false
• 关键词: EAGER; Experimental; Investigation; Forced; Convection

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.

CBET-1449621Kota（新墨西哥州立大学）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众多工艺和设备所固有的，例如发电、热管理、太空运输、水净化和国防领域的热交换器和散热器。在通道/管道中液体的强制对流中，由于流动摩擦和传热性能对流体流速和壁/表面特性的类似依赖性，先前的研究人员发现，任何降低壁处摩擦的尝试都不可避免地会导致传热速率降低和增强传热的努力几乎总是导致摩擦流阻力增加。虽然增强传热是有益的，但壁上摩擦力的增加需要更多的电力消耗，以克服它所需的泵功率的形式。该提案旨在解决这个在过去几十年中引起了广泛研究关注的重要而艰巨的问题，即它能够减少流体流动的壁附近的摩擦，但首次通过采用液体-热传递性能，对传热性能的影响可以忽略不计。饱和分层微/纳米多孔表面。重点将放在无相变的液体强制对流上。拟议的工作对科学和社会具有更广泛的影响，这将通过新墨西哥州立大学本科生和研究生级别的课程整合和最先进的研究/课堂机会得到证明。这项活动将直接帮助培养一支多元化、具有全球竞争力的 STEM 劳动力队伍，他们将了解和解决国家能源利益的关键问题。为了实现项目目标，将在内部制造具有各种粗糙度拓扑的坚固的分层微/纳米多孔表面。使用新型蚀刻技术的流道表面，以及它们的润湿、老化和坚固性方面将使用精确的重量测量和荧光显微镜技术进行表征。为了验证显示该概念巨大潜力的理论预测，将在微型/微通道中对常见冷却剂的强制对流换热性能进行实验研究，水饱和微/纳米孔壁表面。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，该指标将是在相同泵功率下通过规则/平滑的相同尺寸通道泵送相同液体所需的增加的努塞尔数表面。该项目成功完成的结果将产生新的知识库，通过提供关于表面亲和性和鲁棒性、流动稳定性和热传输及其对表面拓扑的依赖性的新颖的基本见解，实现强制对流传输中显着的能源效率。