Periodic Structures in Pool Fires

池火中的周期性结构

• 批准号: 8718921
• 负责人: Timothy Troutt
• 金额: --
• 依托单位: Washington State University
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-03-15 至 1992-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8718921&HistoricalAwards=false
• 关键词: Periodic; Structures; Pool; Fires

Large vortical structures have been observed to form at the base of moderate sized fires and to propagate upwards as the fuel and air are mutually consumed. This research seeks to understand how and why these structures form, to quantify their effect on the entrainment of air and the burning rate of the fuel, and to identify the similarities and differences in the near-field fluid mechanics among pool fires, strongly buoyant nonreacting jets, and natural convection above heated horizontal surfaces. Simultaneous measurements are made of the fluctuating concentration and velocity at multiple locations inside a large, low speed helium jet flowing vertically into air to simulate a pool fire. The fluctuating temperature and velocity are measured also above burning alcohol pools up to nearly one meter in diameter. A three-dimensional, transient numerical model of the nonreacting system is being developed to interpret the experimental results. The results of this research will provide a quantitative basis for the prediction of pool fires. Because it will be based on the fundamental interpretation of results from medium-sized plumes experiments, such understanding will be applicable also to fires of larger dimensions, which are of frequent concern to the community (spills, fuel tanks, etc...).

据观察，中等规模火灾的底部会形成大型旋涡结构，并随着燃料和空气的相互消耗而向上传播。 这项研究旨在了解这些结构的形成方式和原因，量化它们对空气夹带和燃料燃烧速率的影响，并确定池火、强浮力非反应射流和加热水平表面上方的自然对流之间近场流体力学的异同。 同时测量垂直流入空气中的大型低速氦射流内多个位置的浓度和速度波动，以模拟池火。 还在直径近一米的燃烧酒精池上方测量波动的温度和速度。 正在开发非反应系统的三维瞬态数值模型来解释实验结果。 这项研究结果将为泳池火灾的预测提供定量依据。 因为它将基于对中型羽流实验结果的基本解释，所以这种理解也适用于社区经常关注的较大尺寸的火灾（泄漏、燃料箱等）。