Collaborative Research: Correlating Large-Scale Visual Structures to Entrainment Mechanisms in Buoyant and Momentum-Driven Plumes

合作研究：将大规模视觉结构与浮力和动量驱动羽流中的夹带机制相关联

• 批准号: 2231781
• 负责人: Alexis Kaminski
• 金额: $ 25万
• 依托单位: University of California-Berkeley
• 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: 2022-12-01 至 2025-11-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2231781&HistoricalAwards=false
• 关键词: Collaborative; Research; Correlating; Large; Scale

This research will explore the development of buoyant plumes, specifically to quantify how physical structures that develop along the plume/ambient interface result from mass transport through an outlet, and how these structures subsequently affect entrainment and mixing. This work will uncover mechanistic differences in plume evolution, depending on source conditions, thus informing transport models to appropriately incorporate physics for these phenomena. This is key to understanding and predicting the fate of nutrients or pollutants from plumes – for example, volcanic ash clouds, discharges into bays or estuaries, and a host of other environmental and industrial flows. While the fluid dynamics community has long acknowledged the range of physical length scales of eddies in turbulent flows, there exists a lack of research regarding how the exterior structure of a plume or jet is linked to the source conditions. Knowledge uncovered through this research will provide robust means for quantifying plume dynamics through image analysis of remotely acquired data. The research will support the training of two graduate students and undergraduate researchers. The research team will develop workshops for local outreach and educational programs, and data from the outreach events will be used in the research mission. Finally, this project will form the basis for a project for a graduate student in the WHOI summer program in Geophysical Fluid Dynamics.Laboratory experiments and direct numerical simulations will be conducted to satisfy two primary objectives. The first goal is to develop techniques to identify and quantify features comprising the plume structure to remotely determine source conditions of industrial or natural plumes from video or photographic recordings. The second goal is to investigate mechanisms of mixing and entrainment at the plume/ambient interface. In laboratory experiments, simultaneous spatio-temporally resolved particle image velocimetry and laser induced fluorescence measurements will be used to quantify the flow field and mass transport, respectively. Time lapse stereo photogrammetry will be used to reconstruct the dynamic three-dimensional outer edge of the plume, from which distributions of the length scales comprising the external structure can be characterized. A complementary suite of direct numerical simulations will be performed in quiescent unstratified and stratified background fluids. The turbulent/non-turbulent interface and the structures driving entrainment and mixing at the plume edges will be identified in the simulation data and subsequently be compared to the laboratory data. This research will enhance our ability to determine source conditions during plume-driven phenomena, including but not limited to volcanic eruptions, forest fires, glacial discharge plumes, undersea dispersion, and disease transmission.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.

这项研究将探讨浮力羽流的发展，特别是要量化物理结构，发展沿着羽流/环境界面的结果从质量运输通过出口，以及这些结构如何随后影响夹带和混合。这项工作将揭示烟羽演变的机制差异，取决于源条件，从而通知运输模型，以适当地将这些现象的物理。这是理解和预测烟羽中营养物质或污染物命运的关键--例如，火山灰云、海湾或河口的排放以及其他许多环境和工业流动。虽然流体动力学界长期以来一直承认湍流中涡流的物理长度尺度范围，但缺乏关于羽流或射流的外部结构如何与源条件相关联的研究。通过这项研究发现的知识将为通过对远程获取的数据进行图像分析来量化羽流动态提供强有力的手段。这项研究将支持两名研究生和本科生研究人员的培训。研究小组将为当地的外联和教育方案举办讲习班，外联活动的数据将用于研究使命。 最后，这个项目将成为WHOI地球物理流体动力学暑期项目研究生项目的基础。实验室实验和直接数值模拟将进行，以满足两个主要目标。第一个目标是开发技术，以确定和量化构成羽流结构的特征，从而从视频或摄影记录中远程确定工业或自然羽流的源条件。第二个目标是调查在羽流/环境界面的混合和夹带的机制。在实验室实验中，同时时空分辨粒子图像测速和激光诱导荧光测量将分别用于量化流场和质量输运。时间推移立体摄影测量将被用来重建的动态三维外边缘的羽流，从该分布的长度尺度，包括外部结构可以被描述。一个补充套件的直接数值模拟将在静态未分层和分层的背景流体。将在模拟数据中确定湍流/非湍流界面以及驱动卷吸和羽流边缘混合的结构，并随后与实验室数据进行比较。这项研究将提高我们在羽流驱动现象中确定源条件的能力，包括但不限于火山爆发，森林火灾，冰川排放羽流，海底扩散和疾病传播。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。