A bio-inspired strategy to dramatically reduce drag of particle-laden liquids over planar surfaces: characterization, theory and experiment

这个建议描述了一个统一的研究，将揭示在一个悬浮液流过壁面的滑移型边界条件存在的颗粒的运动的相互作用。这项研究是变革性的，因为它将是第一个全面解决含颗粒液体在软多孔材料上的缓慢运动及其相关减阻问题的研究。该项目将大大推进对高度可压缩多孔介质中浆料流动行为的理解，其中纤维可以作为润滑层，具有极大地增加升力和减少阻力的潜力。开发的实验方法和分析技术也可以应用于悬浮液和非牛顿流体在广泛的结构化/图案化表面，如疏水表面的运动。所收集的见解可以显着推进基于微流体的设备在广泛的工业应用，包括生物医学领域，化学合成，（细胞）生物学，食品和制药，以大大减少摩擦和磨损，从而提高这些设备的效率和工作寿命。将通过向工科学生介绍作为非牛顿流体力学及其与多孔介质相互作用的示例的悬浮流来创建该统一主题的教材。本科生将通过麦克奈尔夏季研究计划，克拉克森的REU可持续发展计划，克拉克森的荣誉计划，或通过研究选修课参与该项目的研究人员。拟议研究的目标是为理解载有颗粒的液体在软多孔材料上的流动提供基础，并利用这种理解来探索一种新的生物启发概念，以大大提高润滑压力，同时大大降低摩擦和阻力。这个概念的灵感来自于红细胞通过毛细血管的几乎无摩擦的运动，涉及用具有特定渗透性和孔隙率的软多孔材料阵列覆盖平面表面。该项目的目标是：1）通过将Brinkman方程与扩散通量模型相耦合，并建立耦合流的标度律，开发一种分析模型，该模型准确描述了泥浆在具有特定机械性能的随机软多孔介质阵列上的缓慢运动，以及2）通过使用压降作为测量阻力减小和磁共振成像（MRI）和粒子-图像测速（PIV）测量流体速度。

This proposal describes a unified study that will reveal the interactions of the motion of particles in a suspension flowing over a wall where slip-type boundary conditions exist. This research is transformative because it will be the first to comprehensively address the slow motion of particle-laden liquids over soft porous material and its related drag reduction. This project will substantially advance understanding of the behavior of slurry flows over highly compressible porous media in which the fiber can act as a lubricating layer, with the potential to vastly increase lift and reduce drag. The experimental methods and analysis techniques developed could also be applied to the motion of suspensions and non-Newtonian fluids over a broad array of structured/patterned surfaces such as hydrophobic surfaces. The insights gathered could significantly advance microfluidic-based devices in a wide range of industrial applications including, biomedical fields, chemical synthesis, (cell) biology, food, and pharmaceutics to drastically reduce friction and wear, leading to improved efficiencies and operating lifetimes for these devices. Teaching materials for this unified subject will be created by introducing suspension flows as an example of non-Newtonian fluid mechanics and their interaction with porous media to the engineering students. Undergraduates will participate as researchers in this project through the McNair summer research program, Clarkson's REU program in Sustainability, Clarkson's Honors program, or through a research elective. The goal of the proposed research is to provide the basis for understanding the flow of particle-laden liquids over soft porous materials, and use that understanding to explore a new bio-inspired concept for greatly enhancing the lubricating pressure while dramatically reducing friction and drag in a particle-laden slurry flowing over planar surfaces. This concept, inspired by the almost frictionless movement of red blood cells through capillaries, involves covering the planar surfaces with an array of soft porous material with a specific permeability and porosity. The objectives of the proposed project are to 1) develop an analytical model that accurately describes the slow motion of slurries over random arrays of soft porous media with specific mechanical properties by coupling the Brinkman equation with the diffusive flux model, and establishing scaling laws for coupled flows, and 2) experimentally validate that model by a specially designed experimental set-up using pressure drop as a means to measure drag reduction and magnetic resonance imaging (MRI) and particle-image velocimetry (PIV) to measurement fluid velocities.