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: 2231780
• 负责人: Blair Johnson
• 金额: $ 25万
• 依托单位: University of Texas at Austin
• 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=2231780&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.

这项研究将探索浮体羽毛的发展，特别是为了量化沿李子/环境界面的物理结构如何通过出口质量传输而产生的物理结构，以及这些结构随后如何影响入口和混合。这项工作将根据源条件而发现羽流演化的机械差异，从而告知运输模型以适当地纳入这些现象的物理学。这是理解和预测羽毛营养物或污染物的命运的关键，例如，火山灰云，将其排放到海湾或河口，以及许多其他环境和工业流。尽管流体动力学界长期以来已经认识到湍流中涡流的物理长度尺度的范围，但缺乏研究羽流或喷气机的外部结构如何与源条件相关的研究。通过这项研究发现的知识将提供可靠的手段，用于通过远程获取数据的图像分析来量化李子动态。该研究将支持两名研究生和本科研究人员的培训。研究小组将开发针对当地推广和教育计划的研讨会，研究任务中将使用外展活动的数据。最后，该项目将构成WHOI夏季地球物理动力学的研究生项目的基础。实验室实验和直接数值模拟将满足两个主要目标。第一个目标是开发技术来识别和量化完成羽流结构的功能，以从视频或摄影录音中远程确定工业或自然羽流的来源条件。第二个目标是研究羽流/环境界面处的混合和入口机制。在实验室实验中，简单的空间 - 周期性分辨的粒子图像速度法和激光诱导的荧光测量将分别用于量化流场和质量传输。延时立体摄影将用于重建羽流的动态三维外边缘，从中可以表征完成外部结构的长度尺度的分布。完整的直接数值模拟套件将在静止的未分层和分层背景流体中进行。将在模拟数据中鉴定出湍流/非扰动界面以及在羽流边缘的结构驱动入口和混合，然后将其与实验室数据进行比较。这项研究将增强我们在羽流驱动现象中确定原始状况的能力，包括但不限于火山喷发，森林火灾，冰川排放羽毛，海底分散和疾病传播。这一奖项反映了NSF的法定任务，并通过基金会的知识优点和广泛的影响来诚实地通过评估来诚实地进行支持，以诚实地进行评估。