ISS: Inertial Spreading and Imbibition of a Liquid Drop Through a Porous Surface

ISS：液滴通过多孔表面的惯性扩散和吸入

• 批准号: 1637531
• 负责人: Michel Louge
• 金额: $ 30万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1637531&HistoricalAwards=false
• 关键词: ISS; Inertial; Spreading; Imbibition; Liquid

PI: Louge, MichelProposal Number: 1637531The proposed research will utilize the microgravity environment on the International Space Station (ISS) to improve understanding of imbibition, a process in which water is absorbed by solids. An array of capillaries is going to be used as the experimental set up for investigating contact line pinning and de-pinning as a liquid wets the capillaries. The reason for conducting experiments at the ISS is to take advantage of the long time scales for these phenomena that increases when there is no gravity in space, so that the measurement resolution is much higher than on Earth. The imbibition process is important to many engineering and industrial processes. For example, understanding of how solids and liquids interact, can lead to major improvements in flooding control, which is estimated to cause $11 billion annually. Another engineering application of this work is the process of wet granulation, an important process used by pharmaceutical companies for drug manufacturing. The PIs propose to exploit the OASIS facility on the ISS to observe the imbibition of water into well-characterized cylindrical capillaries on time and length scales long enough to observe details hitherto inaccessible under Earth gravity. The data set will be used as a benchmark for validating numerical simulations on complex capillary geometry. When a drop touches a porous medium, it spreads as if laid on a composite surface. The surface first behaves as a hydrophobic material, as liquid must penetrate pores filled with air. When contact is established, some of the liquid is drawn into pores by a capillarity that is resisted by viscous forces growing with length of the imbibed region. This process always begins with an inertial regime that is complicated by the motion and possible pinning of gas-liquid-solid contact lines jumping over newly-wetted capillaries. A question is whether simulations capture such crucial subtleties. To study imbibition on Earth, time and distance must be shrunk to mitigate gravity-induced distortion. These small scales make it impossible to observe inertial and pinning processes in detail. Instead, OASIS will slowly extrude water spheres until they touch the capillary plate. Their 12mm diameter will be large enough for the GX1050C camera to visualize details near individual capillaries, and long enough to observe dynamics of the entire imbibition process. To investigate the role of contact pinning, it is proposed to test a matrix with ten kinds of porous capillary plates made of metal treated with Self-Assembled Monolayers (SAM), thereby fixing advancing and receding contact angles at known values. These detailed observations will be contrasted with lattice-Boltzmann and Direct Numerical simulations. Prototype testing will take place at Cornell's 1.2s free-fall tower with a unique mechanism producing relatively large water spheres. The wetting of porous surfaces is central to applications where three states of matter coexist, such as fuel cells, filtration, CO2 sequestration, heat pipes, or the wetting of soils. Performance of these systems is determined by capillary forces, geometrical constraints imposed by the contact angle, and contact angle hysteresis. Imbibition can be detrimental (e.g., earth dam collapse after water infiltration), or useful (e.g., irrigation, or wet granulation in drug excipient manufacture). This work will be conducted with undergraduates and a doctoral student. It will also strengthen an outreach program to Technology Education at a local Middle School, which the PI created in 2000.

PI：Louge，MichelProposal编号：1637531拟议的研究将利用国际空间站(ISS)上的微重力环境来提高对吸胀的理解，吸胀是固体吸收水分的过程。一组毛细管将被用作实验装置，用于研究液体润湿毛细管时接触线的钉扎和去钉扎。在国际空间站进行实验的原因是为了利用这些现象的长时间尺度，这些现象在太空中没有重力时会增加，因此测量分辨率比地球上高得多。渗吸过程对许多工程和工业过程都很重要。例如，了解固体和液体是如何相互作用的，可以大大改善洪水控制，据估计，这每年会造成110亿美元的损失。这项工作的另一个工程应用是湿法制粒工艺，这是制药公司用于药物制造的重要工艺。PIS提议利用国际空间站上的绿洲设施，在足够长的时间和长度尺度上观察水对具有良好特征的圆柱形毛细血管的吸收，以观察在地球重力下迄今无法观察到的细节。该数据集将被用作验证复杂毛细管几何形状的数值模拟的基准。当水滴接触到多孔介质时，它会像铺设在复合表面上一样传播开来。表面首先表现为疏水材料，因为液体必须穿透充满空气的毛孔。当建立接触时，一些液体被毛细管吸引到孔隙中，毛细管受到沿吸入区长度增长的粘性力的抵抗。这个过程总是从惯性状态开始，而惯性状态由于气体-液体-固体接触线跳过新湿的毛细管的运动和可能的钉扎而变得复杂。一个问题是，模拟是否捕捉到了如此关键的微妙之处。要研究地球上的吸吸作用，必须缩小时间和距离，以减轻重力引起的扭曲。这些小尺度使得我们不可能详细地观察惯性和钉扎过程。相反，绿洲会慢慢挤出水球，直到它们接触到毛细管板。它们的直径将足够大，足以让GX1050C相机可视化个别毛细血管附近的细节，并足够长，以观察整个吸胀过程的动态。为了研究接触钉扎的作用，建议用10种用自组装单分子膜(SAM)处理的金属制成的多孔毛细管板来测试基质，从而将前进和后退的接触角固定在已知值。这些详细的观测结果将与格子-玻尔兹曼和直接数值模拟进行对比。原型测试将在康奈尔大学1.2s的自由落体塔上进行，其独特的机制可以产生相对较大的水球。多孔表面的润湿是三种物质共存的应用的核心，例如燃料电池、过滤、二氧化碳封存、热管或土壤润湿。这些系统的性能由毛细作用力、接触角施加的几何约束和接触角滞后决定。吸胀可能是有害的(例如，水渗透后土坝坍塌)，也可能是有用的(例如，灌溉，或药物辅料生产中的湿法制粒)。这项工作将与本科生和一名博士生一起进行。它还将加强一项在当地一所中学开展技术教育的外联计划，该计划是由PI于2000年创建的。

项目成果

Statistical mechanics of the triple contact line

三重接触线的统计力学

• DOI: 10.1103/physreve.95.032804
• 发表时间: 2017
• 期刊: Physical Review E
• 影响因子: 2.4
• 作者: Louge, Michel Y.

Model of inertial spreading and imbibition of a liquid drop on a capillary plate

毛细管板上液滴的惯性扩散和吸入模型

• DOI: 10.1002/aic.15953
• 发表时间: 2017
• 期刊: AIChE Journal
• 影响因子: 3.7
• 作者: Louge, Michel Y.;Sahoo, Shilpa
• 通讯作者: Sahoo, Shilpa

Microgravity spreading of water spheres on hydrophobic capillary plates

水球在疏水毛细管板上的微重力扩散

• DOI: 10.1051/epjconf/201714016001
• 发表时间: 2017
• 期刊: EPJ Web of Conferences
• 作者: Steub, Laura;Kollmer, Jonathan;Paxson, Derek;Sack, Achim;Pöschel, Thorsten;Bartlett, John;Berman, Douglas;Richardson, Yaateh;Louge, Michel Y.;Radjai, F.
• 通讯作者: Radjai, F.