ISS: Uncovering transient dynamics and equilibrium states of particle aggregates in fluids

国际空间站：揭示流体中颗粒聚集体的瞬态动力学和平衡状态

• 批准号: 2224469
• 负责人: Raul Cal
• 金额: $ 91.48万
• 依托单位: Portland State University
• 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: 2022-10-01 至 2025-09-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2224469&HistoricalAwards=false
• 关键词: ISS; Uncovering; transient; dynamics; equilibrium

Pollen deposition, paleoecology, algae growth linked to water quality, plastic pollution, and storm transported sea salt in bodies of water are at first examples of particles in fluid-gas interfaces. After a certain time, when and if particles sediment, the dynamics change and the involved processes can become those of a fluid-saturated granular media. Of particular interest for this proposal are externally vibrated particle-laden fluids that are used to segregate different particle sizes and materials, or to fluidize the granular material and thus improve its flow characteristics such as particulate transport and enhanced heat transfer. This project aims at exploring and quantifying transient dynamics of particles in an interface and bulk fluid in the absence of gravity and leading to improved aggregation models. The proposed research represents an important step forward towards the understanding of aggregation of particles in a bulk fluid and gas/fluid interface where times scales are relatively large and the effects are relatively small on Earth. This can aid the improvement of models of these transport phenomena in the overall balance of particle transport processes constantly occurring on Earth. This project is structured such to have a broader impact on the participating students and the broader public.A systematic experimental exploration of aggregation dynamics of particles in an unforced and forced interface and bulk fluid will be pursued. New knowledge and understanding about how these forces affect particle agglomeration rates in the absence of gravity will be created. To elucidate aggregation at liquid-gas interfaces and in a bulk fluid free from gravitational effects, a set of experiments to be performed on the International Space Station is proposed. Drop tower experiments at Portland State University will be performed to narrow parameters relevant to the study to inform relatively long experiments on the International Space Station under zero gravity in collaboration with ZIN Technologies. This project has three main objectives: 1.) Experimentally disentangle the effects on particles of capillary immersion from capillary floating and study the long-term particle dynamics of fluid saturated granular media through a zero-g environment unforced and subjected to an external harmonic forcing; 2.) Quantify collective effects promoted by agglomeration/clustering, particle-fluid and/or particle-particle interactions in a forced and unforced zero-g environment; and 3.) Develop agglomeration models truly representing effects in the absence of gravity on inertial particles. Broader impact activities are coordinated as: 1.) STEM training at the graduate and undergraduate level by a.) Leveraging existing programs at Portland State University as well as b.) Providing experiences to interface with partner company ZIN Technologies and NASA astronauts; and 2.) Oregon Museum of Science and Industry science communication training program will provide an important opportunity for the graduate student and post-doctoral researcher to effectively communicate their science with the broader public.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.

花粉沉积，古生态学，藻类生长与水质，塑料污染和水体中的风暴传输海盐有关，首先是流体气体界面中颗粒的例子。一段时间后，何时及如果颗粒沉积物，动力学变化和所涉及的过程可能会成为流体饱和颗粒培养基的过程。该提案特别感兴趣的是外部振动的含粒子流体，用于隔离不同的粒径和材料，或者将颗粒物材料流化，从而改善其流动特性，例如颗粒传输和增强的传热。该项目旨在在没有重力的情况下探索和量化界面和散装流体中颗粒的瞬时动力学，并导致改善的聚合模型。拟议的研究代表了朝着理解散装流体和气体/流体界面中颗粒聚集的重要一步，在这种研究中，时代尺度相对较大，并且在地球上的影响相对较小。这可以有助于改善这些传输现象的模型在不断发生在地球上的粒子传输过程的总体平衡中。该项目的结构化对参与的学生和更广泛的公众产生了更大的影响。将追求对粒子的聚合动态的系统性实验探索，并将追求颗粒的聚合动力学。将创建有关这些力如何影响粒子聚集率在没有重力的情况下的新知识和理解。为了阐明在液态气体界面和无重力效应的大容量流体中的聚集，提出了一组在国际空间站进行的实验。波特兰州立大学的Drop Tower实验将进行与研究相关的狭窄参数，以告知与ZIN Technologies合作在零重力下在国际空间站的相对较长的实验。 该项目具有三个主要目标：1。）在实验上解散了对毛细血管浸入毛细血管浮动的颗粒的影响，并通过未强制的零G环境研究流体饱和颗粒培养基的长期颗粒动力学，并受到外部和谐强迫的影响； 2.）量化通过强制和未强制的零G环境中的聚集/聚类，颗粒 - 流体和/或粒子粒子相互作用来促进的集体效应； 3.）开发聚集模型在没有重力对惯性颗粒的情况下真正代表影响。 a。）利用波特兰州立大学的现有课程以及b。）提供更广泛的影响活动，为：1。）STEM培训，以及b。）提供与合作伙伴公司Zin Technologies和NASA宇航员交互的经验；和2.）俄勒冈州科学与行业科学传播培训计划将为研究生和博士后研究人员提供一个重要的机会，以便与更广泛的公众有效地传达其科学。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛的影响审查审查标准来通过评估来通过评估来提供支持的。