Collaborative Research: EAGER: Unraveling the Nature and Onset of Instabilities in Suspension Flows

合作研究：EAGER：揭示悬浮液流动不稳定性的本质和发生

• 批准号: 2230893
• 负责人: Michael Schatz
• 金额: $ 9.99万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-15 至 2025-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2230893&HistoricalAwards=false
• 关键词: Collaborative; Research; EAGER; Unraveling; Nature

Flows containing particles (suspension flows) are found in countless settings in nature and in technology; examples range from silt-laden water streaming in a river to blood coursing through a cell-counting analyzer. Pure Newtonian fluids are well-known to undergo instabilities that lead to significant changes in the flow behavior. Suspension flows also experience instabilities; however, the mechanisms that drive suspension flow instabilities are not yet understood. In this project, proven techniques for characterizing instabilities in pure Newtonian fluids will be applied to suspension flows instabilities. This approach should reveal how such instabilities can be probed and manipulated in service of developing better ways to predict how the particles move and are distributed in practical applications. The proposed project is also expected to have significant educational impacts, including providing training on complex flow problem-solving for the next generation of scientists and engineers, attracting and training new graduate and undergraduate students from underrepresented groups and communicating the main ideas in a non-technical form to students at all levels of the educational system and the general public. The primary goal of this project is to demonstrate that the vast fundamental and applied knowledge of instabilities in pure (Newtonian) flows can be harnessed to achieve breakthrough understanding of instabilities in suspension flows. Specifically, this project will test the main Newtonian insight that structuring the flow geometry can unfold the transition process to reveal well-separated, non-turbulent transitions arising from instabilities that can be manipulated by imposing suitably designed perturbations. The project employs new laboratory experiments and existing theory to explore suspension flows in structured channels. First, the laminar steady state will be characterized as a function of Reynolds number for a specified particle size and selected average particle volume fractions. The research then examines both pure Newtonian fluid and suspension flows instabilities. The outcomes of this project should lay the foundations for future studies to investigate new and heretofore uncharted fundamental fluid physics that arises when inertial particles are added to the flow. The results of our work should set the stage for the discovery of new methods to manipulate flow and particles.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在自然界和技术中无数的环境中都发现了含有颗粒的流动（悬浮流）；例子包括从河流中流动的充满淤泥的水到流经细胞计数分析仪的血液。众所周知，纯牛顿流体会经历不稳定性，从而导致流动行为发生显着变化。悬浮液流也会经历不稳定；然而，导致悬浮液流动不稳定的机制尚不清楚。在该项目中，用于表征纯牛顿流体不稳定性的成熟技术将应用于悬浮液流动不稳定性。这种方法应该揭示如何探测和操纵这种不稳定性，以开发更好的方法来预测粒子在实际应用中如何移动和分布。拟议的项目预计还将产生重大的教育影响，包括为下一代科学家和工程师提供解决复杂流程问题的培训，吸引和培训来自代表性不足群体的新研究生和本科生，以及以非非公开方式传达主要思想。向各级教育系统的学生和公众提供技术形式。该项目的主要目标是证明可以利用纯（牛顿）流不稳定性的大量基础知识和应用知识来实现​​对悬浮液流不稳定性的突破性理解。具体来说，该项目将测试牛顿的主要见解，即构造流动几何形状可以展开过渡过程，以揭示由不稳定性引起的分离良好的非湍流过渡，这些不稳定性可以通过施加适当设计的扰动来操纵。该项目采用新的实验室实验和现有理论来探索结构化通道中的悬浮液流动。首先，层流稳态将被表征为特定颗粒尺寸和选定的平均颗粒体积分数的雷诺数的函数。然后，该研究检查了纯牛顿流体和悬浮液流动的不稳定性。该项目的成果应该为未来的研究奠定基础，以研究当惯性粒子添加到流体中时出现的新的和迄今为止未知的基础流体物理学。我们的工作成果应该为发现操纵流动和粒子的新方法奠定基础。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。