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灰烬蓬勃发展到大气中的余烬引起的，并在野火的主要锋线前吹了。这项研究的目的是建立一个经过实验验证的野火飞行的随机模型。该研究计划将建立在Ember Flight的现有确定性模型的基础上，并开发分析和数值模型，以说明问题的固有随机性。这些模型将包括用于灰烬大小和形状，火灾大小和强度的概率分布函数的参数化，以及火羽和大气边界层中的湍流速度波动。这些模型将通过在大规模边界层风洞中进行的一系列Ember飞行实验进行验证。实验将在各种尺寸，形状和风条件下测量高度和下风的传输距离。这将为抬高余烬的飞行距离提供实验测量。经过实验验证的数值模型将用于执行参数灵敏度研究，以建立那些最大程度地影响Ember发现和开始火的风险的参数。现场火灾会造成重大财产损失，并可能危及房主和消防员的生命。了解如何将余烬升至大气中，然后向下吹来的机制将极大地增强我们预测现场火灾风险并改善我们对这种威胁的反应的能力。该项目将通过解决所涉及过程的随机性质来改变Ember Flight的模型。最终目标是减轻野火环境中的点火造成的财产损失。研究团队将制定一项公共外展计划，以向学校学生提供有关野火风险的教育，并鼓励学生从事科学和工程学的职业。外展计划将通过演示在网络上提供的测试和视频以及其他材料来介绍南卡罗来纳州的学校。