Flow physics of wicking into woven screens with hybrid micro-/nanoporous structures
Flow physics of wicking into woven screens with hybrid micro-/nanoporous structures
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芯吸进入具有混合微/纳米孔结构的编织屏幕的流动物理学
DOI：
10.1021/acs.langmuir.0c02872
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发表时间：
2021
期刊：
影响因子：
3.9
通讯作者：
Jingyi Wu
中科院分区：
文献类型：
--
作者：
Ye Wang;Yilin Lin;Guang Yang;Jingyi Wu
由于在相变传热和相分离方面的重要作用，编织筛网内的芯吸引起了相当大的关注。在本研究中，水平铺展实验进行调查的编织屏幕的芯吸性能，通过测量体积的液体进入屏幕和液体的传播前沿，通过两个垂直的高速摄像机。通过扩散结合和化学工艺来操作具有微米（单层和多层）和纳米（普通、蚀刻和氟化）多孔结构的编织丝网。宏观观察表明，在多层结构中的芯吸能力的显着增强，其中层间微通道可以通过提供低阻力流动通道来弥补单层筛网的本质缺陷。水的芯吸能力通过沿着线沿着的亲水性纳米草而增强。此外，通过表观和饱和芯吸距离之间的比较，分析了屏幕内的流动机制。在多层结构中，液体沿着蚀刻筛网中的整个横截面积扩散，而它主要沿着普通筛网和氟化筛网中的层间微通道扩散。各种流体对编织筛网内的芯吸行为的影响被发现完全由一个独特的参数来表示，该参数捕获径向流模型中的表面张力和动态粘度的影响。这项工作加深了对具有混合微/纳米多孔结构的编织筛网内的毛细驱动流动的理解，并为高效芯吸结构的设计和制造提供指导。
Wicking within woven screens has attracted considerable attention due to its important role in applications concerning phase-change heat transfer and phase separation. In the present study, horizontal spreading experiments are conducted to investigate the wicking performance of woven screens by measuring the volumetric liquid intake into the screens and the liquid propagation fronts through two perpendicular high-speed cameras. Woven screens with micro (single- and multilayer)- and nano (plain, etched, and fluoridated)-porous structures are manipulated through diffusion bonding and chemical processes. The macroscopic observation indicates the substantial enhancement of the wicking capability in multilayer structures, where the interlayer microchannels could compensate for the essential deficiency of single-layer screens by providing low-resistance flow passages. Wicking capability of water is enhanced by the hydrophilic nanograsses along the wires. Furthermore, flow mechanisms within the screens are analyzed by comparisons between apparent and saturated wicking distances. In multilayer structures, the liquid spreads along the entire cross-sectional area in etched screens, while it spreads primarily along the interlayer microchannels in plain and fluoridated screens. The influence of various fluids on the wicking behavior within the woven screens is found to be fully represented by a unique parameter that captures the effects of surface tension and dynamic viscosity in the radial flow model. This work deepens the understanding of the capillary-driven flow within the woven screens with hybrid micro-/nanoporous structures and provides guidance for the design and manufacture of highly efficient wicking structures.