COLLABORATIVE RESEARCH: Dynamics of Inertial Particles in Thermally-Stratified Flows within Electromagnetic Field

尽管粒子在工业、环境、健康和国防等领域有着广泛的应用和影响，但粒子在热传输过程中的作用仍然知之甚少。通过表征不同条件下热分层介质中的流体动力学和颗粒，该项目将提供适用于一系列现象的新知识，包括雨的形成、污染物的传输、可吸入颗粒物的传输和在横贯大陆的气体管道中的混合。此外，通过探索使用磁性粒子作为控制机制的可能性，该项目将提供监管工业过程的策略，并有可能提高其效率。这项研究将为工业和生物系统的热混合控制提供见解。该项目将直接促进K-12学生的STEM教育以及研究生和本科生的教育发展；将做出重大努力将结果传播给更广泛的科学界和社会。该项目旨在定量描述并显著提高我们对热层结湍流对流与惯性粒子相互作用所产生的现象的理解。将使用先进的试验性流动诊断工具，以高空间和时间分辨率跟踪大量惯性粒子和流动示踪剂。这项工作将考察调节颗粒动力学的主导因素，颗粒引发的流动不稳定性，优先浓度，颗粒与流动之间的双向和四向耦合。将特别注意通过附加边界条件和对粒子的电磁控制来描述扰动自然对流下的这种现象。分析将包括欧拉和拉格朗日统计，以及大量粒子的高度分辨的轨迹、速度和加速度。结果将揭示控制变量的作用，包括斯托克斯数和瑞利数以及体积分数，这将为在各种应用中控制热过程的战略的制定提供基础。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Despite the multiple applications and impact in industry, environment, health, and defense, the role of particles in thermal transport processes remains poorly understood. By characterizing the fluid dynamics and particles in thermally stratified media under various conditions, the project will provide new knowledge applicable to a range of phenomena including rain formation, pollutant transport, inhaled particulate matter transport and mixing in transcontinental gas ducts. Additionally, by exploring the possibility of using magnetic particles as a control mechanism, the project will offer strategies to regulate industrial processes, with potentially increasing their efficiency. The research will provide insight on the control of thermal mixing for industrial as well as biological systems. The project will directly contribute to STEM education of K-12 students and educational development of both graduate and undergraduate students; significant efforts will be made to disseminate the results to the broader scientific community and to society.The project aims to quantitatively describe and significantly improve our understanding of the phenomena resulting from the interaction between thermally-stratified turbulent convection with inertial particles. Advanced experimental flow-diagnostic tools will be used to track a large set of inertial particles and flow tracers at high spatial and temporal resolutions. The work will examine the dominant factors modulating the dynamics of the particles, flow instability triggered by particles, preferential concentration, two- and four-way coupling between particles and flow. Special attention will be placed on characterizing such phenomena under disturbed natural convection via additional boundary conditions and electromagnetic control on particles. Analysis will include Eulerian and Lagrangian statistics as well as highly resolved trajectories, velocity, and acceleration of large set of particles. Results will uncover the role of control variables including the Stokes and Rayleigh numbers and volume fraction, which will provide basis for the development of strategies to control thermal processes in various applications.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.