Collaborative Research: Laboratory and theoretical study of geyser dynamics

合作研究：间歇泉动力学的实验室和理论研究

• 批准号: 2050352
• 负责人: Maxwell Rudolph
• 金额: $ 10.43万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2050352&HistoricalAwards=false
• 关键词: Collaborative; Research; Laboratory; theoretical; study

With over 4 million annual visitors to Yellowstone's Old Faithful geyser, public fascination with geysers is undeniable. Yet, the scientific understanding of geysers is incomplete. While it has been understood for over a century that geyser eruptions are caused by the sudden boiling of water in underground conduits, scientists do not understand what triggers these boiling events, and how the size and shape of the underground conduits affect a geyser’s behavior. Recent studies at geyser fields in Yellowstone National Park, El Tatio on the Chilean altiplano, and the Geyser Valley in Kamchatka, have shown that the underground plumbing systems at these sites include a reservoir that is offset to the side relative to the main eruption conduit. In such systems, steam gets captured in the side reservoir, earning it the name ‘bubble trap’. The discovery of this geometry is the most significant advance in several decades, but researchers are only beginning to understand how it affects a geyser's behavior. This team will create a small geyser setup in the laboratory that will include a bubble trap. They will run a series of experiments to study how fluids behave in this type of system. The proposed work will use mathematical models to relate behaviors observed in the lab to the much larger systems that we encounter in nature. The project will provide research experiences for undergraduate students and will contribute instructional materials to educators through an established teacher training program. The laboratory geyser will be exhibited at the Lamont Doherty Earth Observatory open house, visited by thousands of people each year.Geysers represent a unique class of hydrothermal systems where the thermodynamics of two-phase (vapor and liquid) flow and favorable conduit geometries combine to produce episodic eruptions. With over 4 million annual visitors to Yellowstone's Old Faithful geyser, public fascination with geysers is undeniable, but our scientific understanding of geysers is incomplete. Recently, however, data from geyser fields in Yellowstone National Park, El Tatio on the Chilean altiplano, and the Geyser Valley in Kamchatka, have provided compelling evidence for conduit geometries that include a reservoir that is laterally offset from the eruption conduit. This so-called 'bubble trap' geometry allows compressed steam to accumulate under an impermeable roof, and its discovery has revitalized geyser research as this team seeks to understand its implications for a geyser's dynamic behavior. None of the laboratory geyser experiments developed to-date accurately simulates the full range of behaviors observed in natural systems, and the effects of bubble trap conduit geometries have not been explored thoroughly. Similarly, mathematical models have informed geyser research for more than a century, but none of the extant models considered the full range of thermodynamic and fluid mechanics processes associated with a bubble trap conduit geometry. This project will address both of these shortcomings by combining novel laboratory experiments that include the missing pieces for geysers with a bubble trap. The laboratory analog geyser will provide an idealized representation of the thermodynamic processes and subsurface geometries of natural geysers, enabling a series of experiments aimed at elucidating the fluid mechanical and thermodynamic behaviors of the geyser system. In parallel, mathematical models will be developed to describe the system behavior, and these relationships will be used to improve our understanding of natural systems. The laboratory geyser will enable the evaluation of competing hypotheses for eruption triggering, and comprehensive monitoring instrumentation will enable the observation of geyser processes in unprecedented detail.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.

黄石老忠实间歇泉每年吸引超过 400 万名游客，不可否认，公众对间歇泉的迷恋是不完整的，尽管一个多世纪以来人们一直认为间歇泉喷发是由水突然沸腾引起的。地下管道，科学家们不明白是什么触发了这些沸腾事件，以及地下管道的大小和形状如何影响间歇泉的行为。黄石国家公园、智利高原上的埃尔塔蒂奥和堪察加间歇泉谷的油田表明，这些地点的地下管道系统包括一个相对于主要喷发管道向一侧偏移的水库。这种几何形状的发现是几十年来最重大的进步，但研究人员才刚刚开始了解它如何影响间歇泉的行为。他们将在实验室中创建一个小型间歇泉装置，其中包括一个气泡捕集器。他们将进行一系列实验来研究流体在此类系统中的行为。拟议​​的工作将使用数学模型将实验室中观察到的行为与实际情况联系起来。该项目将为本科生提供研究经验，并通过既定的教师培训计划为教育工作者提供教学材料。实验室间歇泉将在拉蒙特·多尔蒂地球观测站开放日展出，吸引数千人参观。每个人的间歇泉代表了一类独特的热液系统，其中两相流（蒸汽和液体）的热力学和有利的管道几何形状相结合，产生间歇性喷发。每年有超过 400 万游客参观黄石公园的老忠实间歇泉，公众对间歇泉的迷恋越来越强烈。不可否认，但我们对间歇泉的科学认识并不完整，然而，最近来自智利黄石国家公园埃尔塔蒂奥间歇泉田的数据。阿尔蒂普拉诺和堪察加半岛的间歇泉谷为管道几何形状提供了令人信服的证据，其中包括与喷发管道横向偏移的水库，这种所谓的“气泡陷阱”几何形状允许压缩蒸汽积聚在不渗透的屋顶及其下。这一发现重振了间歇泉研究，因为该团队试图了解其对间歇泉动态行为的影响，迄今为止开发的实验室间歇泉实验都无法准确模拟完整的间歇泉。同样，一个多世纪以来，数学模型一直在为间歇泉研究提供信息，但现有的模型都没有考虑到热力学和流体的全部范围。该项目将通过结合新颖的实验室实验来解决这两个缺点，其中包括间歇泉与气泡陷阱的缺失部分，实验室模拟间歇泉将提供热力学过程的理想化表示。天然间歇泉的地下几何形状，使得能够进行一系列旨在阐明间歇泉系统的流体力学和热力学行为的实验，同时，将开发数学模型来描述系统行为，并且这些关系将用于增进我们对间歇泉的理解。实验室间歇泉将能够评估喷发触发的竞争假设，而综合监测仪器将能够以前所未有的细节观察间歇泉过程。该奖项反映了 NSF 的法定使命，并被认为值得支持。通过使用基金会的智力优点和更广泛的影响审查标准进行评估。