Experimental and Modeling Study of Risk from Ember Storms

余烬风暴风险的实验和建模研究

• 批准号: 1200560
• 负责人: Nigel Kaye
• 金额: $ 20.04万
• 依托单位: Clemson University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-15 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1200560&HistoricalAwards=false
• 关键词: Experimental; Modeling; Study; Risk; Ember

Spot fires in wildfire environment are caused by embers lofted into the atmosphere and blown well ahead of the main front of the wildfire. The objective of this research is to establish an experimentally verified stochastic model for ember flight in wildfires. The research program will build on existing deterministic models for ember flight and develop analytical and numerical models that account for the inherently stochastic nature of the problem. The models will include parameterizations of the probability distribution functions for ember size and shape, fire size and intensity, and the turbulent velocity fluctuations in fire plume and the atmospheric boundary layer. The models will be verified through a series of ember flight experiments conducted in a large scale boundary layer wind tunnel. The experiments will measure lofting height and downwind transport distance for a broad range of sizes, shapes, and wind conditions. This will provide experimental measurements of the flight distance for lofted embers. The experimentally verified numerical model will be used to perform parametric sensitivity studies to establish those parameters that most greatly influence the downwind risk of ember spotting and starting fire. The spot fires can cause significant property damage and can endanger the lives of home owners and firefighters. Understanding the mechanics of how embers are lofted up into the atmosphere and then blown downwind will greatly enhance our ability to predict the risk of spot fires and improve our response to such threats. The project will transform the way that ember flight is modeled by addressing the random nature of the processes involved. The ultimate goal is to mitigate property losses caused by spot fires in wildfire environment. The research team will develop a public outreach program to educate school students about the risks from wildfires, and to encourage students to pursue careers in science and engineering. The outreach program will be focused on South Carolina schools through demonstrations of the tests and videos and other materials that will be made available on the web.

野火环境中的点火是由余烬进入大气层并在野火的主要前沿吹走而引起的。本研究的目的是建立一个实验验证的随机模型在野火中的飞行。该研究计划将建立在现有的确定性模型的飞行和发展的分析和数值模型，占固有的随机性质的问题。这些模型将包括火灾规模和形状、火灾规模和强度的概率分布函数的参数化，以及火羽流和大气边界层中的湍流速度波动。这些模型将通过在大型边界层风洞中进行的一系列连续飞行实验进行验证。实验将测量各种尺寸、形状和风力条件下的放样高度和顺风运输距离。这将提供实验测量的飞行距离为放样余烬。实验验证的数值模型将用于进行参数敏感性研究，以确定那些最大程度地影响顺风点和着火风险的参数。现场火灾可能造成重大财产损失，并可能危及业主和消防队员的生命。了解余烬是如何上升到大气中，然后被顺风吹走的机制，将大大提高我们预测火灾风险的能力，并改善我们对此类威胁的反应。该项目将通过解决所涉及的过程的随机性来改变模拟飞行的方式。其最终目的是减轻野火环境中点火造成的财产损失。该研究小组将制定一项公共宣传计划，教育学校学生有关野火的风险，并鼓励学生从事科学和工程职业。推广计划将集中在南卡罗来纳州的学校，通过演示的测试和视频和其他材料，将在网上提供。