Particle Migration in Complex Viscous Flows

复杂粘性流中的粒子迁移

• 批准号: 0334825
• 负责人: Joseph McCarthy
• 金额: $ 15万
• 依托单位: University of Pittsburgh
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0334825&HistoricalAwards=false
• 关键词: Particle; Migration; Complex; Viscous; Flows

AbstractCTS-0334825J. McCarthy, U of PittsburghThis proposal is focused on the migration of non-neutrally bouyant particles in complexnon-Stokesian closed flows. This problem, important to issues ranging from materials processing to reactor design, has not been studied either computationally or experimentally, to our knowledge. The central hypothesis of the proposed work is that in these flows the variety of migration forces -- centrifugal and gravitational buoyancy; a variety of inertial lift forces (both with spin and without); and shear-induced migration when multiple particles are present -- can lead to a rich variety of asymptotic behavior. Furthermore, with recent advances in both experimental flow visualization as well as multi-phase Computational Fluid Dynamics (CFD), we believe that strong insight into particle migration in complex flows is now possible. In this work, we focus on the migration behavior of non-neutrally buoyant particles in two prototypical non-Stokesian closed flows: a cavity flow and a mixing tank. Specifically, the research will examine the trajectories and asymptotic locations of particles both computationally and experimentally, with the ultimate aim of uncovering the competition between migration modes such that control of asymptotic particle behavior may be possible.The broader impact of the work lies in integration of research and teaching, infrastructure development, and the fostering of partnerships. During the course of the project training will be provided for one full-time graduate student. Every effort will be made to recruit students from underrepresented groups to participate in this endeavor. Similarly, several undergraduate researchers will be involved in the form of an independent study (thus integrating research and teaching without requiring additional budgeted funds). The proposed work will enhance infrastructure through the generation of both the experimental data (as a metric of comparison for future work) as well as by comparing/validating several computational techniques for modeling particle migration in complex flows. It will foster partnerships by enabling future collaborative work between the PI and the National Energy Technology Laboratory. The intellectual merit of the proposal lies in gaining a better fundamental understanding of the migration forces relevant in complex viscous flows. At the completion of the project we will have advanced discovery and understanding through (1) establishing well-documented experimental results on particle migration in complex flows (2) validating pseudo-continuum and discrete modeling tools for examining these flows; and ultimately, (3) developing methodologies which exploit competing effects within these systems to yielda rational procedure for varying particle properties (size, shape, density), fluid properties (density, viscosity), and flow field/geometry such that the discrete elements within a flow migrate to well-defined predetermined positions.

Abstractcts-0334825J。匹兹堡Thiss u的U麦卡锡（McCarthy）集中于复杂的诺农 - 斯托克斯封闭流中的非独立偏见颗粒的迁移。据我们所知，这个问题对于从材料处理到反应堆设计的问题很重要，尚未在计算或实验上进行研究。提议的工作的中心假设是，在这些流动中，各种迁移力量 - 离心和重力浮力；各种惯性升力力（无论是自旋还是没有）；当存在多个粒子时，剪切诱导的迁移 - 可能导致各种渐近行为。 此外，随着实验流可视化以及多相计算流体动力学（CFD）的最新进展，我们认为现在可以对复杂流中粒子迁移的强烈了解。在这项工作中，我们着重于两个典型的非Stokesian封闭流中非中性浮力颗粒的迁移行为：一个腔流和一个混合罐。具体而言，该研究将在计算和实验上检查颗粒的轨迹和渐近位置，其最终目的是揭示迁移模式之间的竞争，以控制渐近粒子行为的控制可能是可能的。该工作的更广泛影响在于研究，基础设施发展的整合，基础设施发展，以及集团的寄养。在项目期间，将为一名全日制研究生提供培训。将竭尽全力招募来自代表性不足的团体的学生参加这项工作。同样，一些本科研究人员将参与独立研究的形式（从而整合研究和教学而无需额外的预算基金）。提出的工作将通过生成实验数据（作为对未来工作的比较度量）以及比较/验证几种用于建模复杂流中粒子迁移的计算技术来增强基础架构。它将通过实现PI与国家能源技术实验室之间的未来合作工作来促进合作伙伴关系。该提案的智力优点在于，对复杂粘性流中相关的移民力量有了更好的基本理解。项目完成后，我们将通过（1）建立有关复杂流中粒子迁移的实验结果的高级发现和理解（2）验证伪continuum和用于检查这些流量的离散建模工具；最终，（3）开发方法学，从这些系统中利用竞争效应来产生不同粒子特性（尺寸，形状，密度），流体特性（密度，粘度）和流场/几何形状的方法，从而使流动中的离散元素迁移到定义明确的预定位置。