Large Scale Molten Fuel Coolant Interaction Experiments: Explosion Initiation and Propagation

大规模熔融燃料冷却剂相互作用实验：爆炸引发和传播

• 批准号: 1347992
• 负责人: Ingo Sonder
• 金额: $ 29.35万
• 依托单位: SUNY at Buffalo
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1347992&HistoricalAwards=false
• 关键词: Large; Scale; Molten; Fuel; Coolant

1347992SonderThis grant supports development of an experimental capability to control influencing parameters and study the behavior of phreatomagmatic events. Specifically, the PIs will develop a significantly and, as of yet unexplored, up-scaled device for controlling and observing the behavior of triggered explosive phreatomagmatic volcanism by: 1) assembling and developing a tiltable furnace for melting natural igneous rock; 2) developing a 25-50 L insulated crucible into which the melt would be poured and through the base of which water can be injected at various isolated points throughout the melt to create a phreatomagmatic ?premix? in which a quasi-stable water vapor phase separates the liquid water from the melt; 3) developing a trigger system (e.g., an air gun directed into the crucible containing the premix or a hammer device) to induce breakdown of separating water vapor phase such that direct interaction of hot magma and liquid water causes rapid cooling and leads to explosive volcanism; and 4) instrumenting the crucible with observation methodologies to study the mechanical and dynamical behavior of the system (e.g., high-speed force transducers mounted on the bottom of the crucible to measure the vertical forces of explosion, thermocouples within the crucible to measure melt temperatures, high speed cameras to observe ejecta). The development of the device will involve consultation with scientists at Wurzburg University in Germany and engage a Ph.D. student in instrument system engineering and experimentation. Initial experiments will varying the pre-mix parameters (injected water geometry and volumes and preloading of water down the crucible supply ramp ? dynamic premix), testing differing triggering mechanisms and subsequent study of ejecta (e.g., grain size analysis, spatial distribution, textural and mineralogical study of ash minerals). Melt composition will be maintained as a constant for experiments. The explosive experiments will be carried out at an extant outdoor facility (the GeoHazards Field Station leased by SUNY-Buffalo that is already permitted for explosives. The proposed scale of the device represents the potential for a two order of magnitude increase in the volume of magma premix that has hitherto been experimentally controlled to study phreatomagmatism and presents an interesting mid-scale parameter space to study of phreatomagmatic behavior and the conditions that favor hazardous ash clouds and pyroclastic density current formation. This scale of experiment is far from the scale of natural systems, but should offer new insights into questions surrounding the nature of phreatomagmatism including: 1) what is the influence of many water domains entrapped in the melt on explosion intensity when they are homogeneously and inhomogeneously distributed? and 2) is there a minimum trigger energy necessary to start the explosion, or can a premix effectively explode by itself? Experimental results will feed into models that attempt to scale laboratory observations to natural system behavior.***

1347992Sonder 这项拨款支持开发控制影响参数和研究热岩浆事件行为的实验能力。 具体来说，PI将开发一种迄今为止尚未探索的重要的升级装置，用于控制和观察引发的热岩浆火山活动的行为：1）组装和开发用于熔化天然火成岩的可倾斜熔炉； 2) 开发一个 25-50 L 的绝缘坩埚，将熔体倒入其中，并通过坩埚底部在整个熔体的各个隔离点注入水，以形成风岩“​​预混料”。其中准稳定的水蒸气相将液态水与熔体分离； 3) 开发触发系统（例如，将气枪导入装有预混料的坩埚或锤装置）以诱导分离水蒸气相的分解，从而使热岩浆和液态水的直接相互作用导致快速冷却并导致爆炸性火山活动; 4) 使用观察方法对坩埚进行仪表化，以研究系统的机械和动态行为（例如，安装在坩埚底部的高速力传感器用于测量爆炸的垂直力，坩埚内的热电偶用于测量熔体温度，高速摄像机观察喷射物）。 该设备的开发将涉及与德国维尔茨堡大学的科学家进行协​​商，并聘请博士。仪器系统工程与实验专业的学生。 初始实验将改变预混合参数（注入水的几何形状和体积以及沿着坩埚供应坡道预加水？动态预混合），测试不同的触发机制和喷射物的后续研究（例如，粒度分析、空间分布、结构和灰矿物的矿物学研究）。 实验中熔体组成将保持恒定。 爆炸实验将在现有的室外设施（纽约州立大学布法罗分校租用的地质灾害现场站，已允许进行爆炸物）进行。拟议的设备规模代表岩浆体积可能增加两个数量级迄今为止已通过实验控制的预混物，用于研究热岩浆作用，并提供了一个有趣的中尺度参数空间，用于研究热岩浆行为以及有利于危险灰云和火山碎屑密度的条件这种实验规模远未达到自然系统的规模，但应该为围绕热岩浆作用性质的问题提供新的见解，包括：1）熔体中的许多水域在它们形成时对爆炸强度有什么影响。均匀分布和非均匀分布？ 2) 是否存在启动爆炸所需的最小触发能量，或者预混料能否有效地自行爆炸？ 实验结果将输入模型，尝试将实验室观察扩展到自然系统行为。***