Collaborative Research: A Micropatterned Wettability Approach for Superior Boiling Heat Transfer Performance

CBET-1235867 PI：丹尼尔·阿廷格（爱荷华州州立大学）和C.这个跨机构的项目跨越热流体工程，材料科学和优化领域，主要目标是设计，制造和研究新的表面，被称为？超嗜性这些微结构和纳米结构表面将超疏水区域（对水具有强亲和力）与超疏水区域（对水蒸气具有强亲和力）并置。因此，它们通过以并行和最佳方式控制汽相和液相的输送而在池沸腾中显示出上级性能。该研究将开发一种新型的金属涂层工艺，该工艺可扩展且与工业热交换器相关。主要的科学挑战在于理解，控制和优化超双亲表面上的沸腾现象。第一次，双亲和超双亲表面将在技术上相关的金属基材上制造。该技术基于可喷涂图案涂层，这是一个美国领导地位受到海外挑战的工业领域。该研究为双亲和超双亲表面的沸腾强化奠定了理论基础。这项工作具有挑战性，因为沸腾涉及多相和多尺度传输现象（蒸发开始于亚微米厚的膜，而分离的气泡是毫米级的）和严重的瞬态过程。为了协助设计和实验，将进行建模工作。对于简单的表面形貌（或模式的疏水和亲水域），分析模型将开发解释池沸腾增强定性的方式。还将进行计算流体动力学模拟，以帮助理解实验数据，确定负责沸腾增强的动态机制，并评估复杂表面形貌的性能。这项工作将采用一种模式设计优化方法来确定沸腾性能的最佳拓扑结构。通过一系列实验，包括表面润湿性测量、涂层物理表征、高速可视化以及成核和池沸腾曲线，对新型超双亲表面的性能进行评估。该研究涉及多学科主题中丰富的基本现象，旨在提供一种创新的解决方案，以在沸腾配置中以上级速率传递热量。这项工作的发展将影响-除其他技术外-热交换器，热交换器广泛用于大多数能源密集型行业，仅在美国每年就消耗超过15千英热单位。因此，这项研究带来的非增量改进有可能产生巨大的能源节约，从而减少能源浪费和环境污染。两名研究生将在这个项目中接受教育，该团队将接触芝加哥地区代表性不足的少数民族。

CBET-1235867PIs: Daniel Attinger (Iowa State Univ.) and C. Megaridis (UIC)This cross-institutional project straddles the areas of thermofluid engineering, materials science and optimization, with main goal to design, fabricate and study novel surfaces that are called ?superbiphilic.? These micro- and nanostructured surfaces juxtapose superhydrophobic areas (with strong affinities for water) with superhydrophobic areas (with strong affinities for water vapor). As such, they show superior performance in pool boiling by controlling the transport of the vapor and liquid phases in a parallel and optimal manner. The study will develop a novel coating-on-metal process, which is scalable and relevant to industrial heat exchangers. The main scientific challenge lies in understanding, controlling and optimizing boiling phenomena on the superbiphilic surfaces. For the first time, biphilic and superbiphilic surfaces will be fabricated on technically relevant, metallic substrates. The technology is based on sprayed-on patternable coatings, an industrial sector where US leadership is challenged from overseas. The research will develop a theoretical science base for boiling enhancement on biphilic and superbiphilic surfaces. The work is challenging because boiling involves multiphase and multiscale transport phenomena (evaporation starts in a sub-micrometer thick film, while detaching bubbles are millimeter-sized) and severely transient processes. To assist with the design and experiments, a modeling effort will be carried through. For simple surface topographies (or patterns of hydrophobic and hydrophilic domains), analytical models will be developed to explain the pool boiling enhancement in a qualitative manner. Computational fluid dynamic simulations will also be performed, to help understand the experimental data, identify the dynamic mechanisms responsible for the boiling enhancement, and evaluate the performance of complex surface topographies. The effort will feature a pattern design optimization approach to determine optimum topographies for boiling performance. The performance of the novel superbiphilic surfaces will be evaluated by a series of experiments, including surface wettability measurements, coating physical characterization, high speed visualization, as well as nucleation and pool boiling curves.The research, which involves rich fundamental phenomena in a variety of multidisciplinary topics, intends to deliver an innovative solution to transferring heat at superior rates in boiling configurations. The developments from this work will affect -among other technologies- heat exchangers, which are widely used in most energy-intensive industries, which collectively consume over 15 quadrillion Btu/yr in the US alone. Consequently, the non-incremental improvements resulting from this research have the potential to generate tremendous energy savings, and in turn, reduce energy waste and environmental pollution. Two graduate students will be educated in this program, and the team will reach out to underrepresented minorities in the Chicago area.