森林爆发火的形成机制与动力学规律基础研究

Eruptive fire is a typical extreme fire behavior in wildland fires, characterized by the sudden acceleration of fire spread rate under certain fuel and topography conditions. Eruptive fire has been often reported in large wildland fires, with great losses to life and property. Due to the complexity of physical interactions between flow and combustion, there have been only very limited reports on the study of eruptive fire, and the formation mechanism of eruptive fire is still far from being fully elucidated. Especially there is obvious lack of consistent experimental work on eruptive fire. This project will systematically investigate the flame combustion dynamics and heat transfer under different fuel and topography conditions, by experimental and theoretical analyses. The dynamical behaviors of flame tilting and nonlinear flame front under different slope angles will be studied, in order to reveal the effect of slope on the flame radiation and convection heat transfer in fire spread. Also, the mechanism of flame attachment in canyon topography and the relevant heat transfer mechanisms will be investigated. The mechanism of flame acceleration and the critical conditions for formation of eruptive fire are expected to be systematically elucidated. The final output of the project will be the theoretical model of eruptive fire addressing the interaction of flow and combustion, which is expected to be of highly theoretical value for early warning of eruptive fire in wildland fires.

爆发火（Eruptive fire）是森林火灾中一种以火蔓延显著加速为特征的典型极端火行为，是人类应对森林大火所面临的重要威胁之一。由于涉及流动与燃烧的复杂物理耦合作用机制，迄今针对爆发火的研究工作尚属初步，还远不能对爆发火形成的动力学机理赋予完备解释，系统性的实验研究尤为缺乏。本项目借助实验模拟和理论建模，系统研究在不同燃料和地形条件下火蔓延的火焰燃烧动力学和热量输运变化机制与规律，由此一方面揭示坡度作用下的火焰前倾和非直线火前锋动力学行为及其火焰辐射与对流传热机制与规律，另一方面揭示峡谷地形中火焰附着的物理机制和热量输运规律，在此基础上，系统阐释火蔓延加速及其诱发爆发火的物理机制和临界条件，建立体现流动-燃烧复杂耦合机制与规律的爆发火动力学模型。项目可为爆发火预警方法的建立提供可靠的科学依据，具有重要的基础科学意义和应用价值。

森林爆发火是一种以火蔓延速率陡增为特征的森林极端火行为。本项目借助实验模拟和理论建模，系统研究在不同燃料和地形条件下火蔓延的火焰燃烧动力学和热量输运变化机制与规律，揭示了斜坡火蔓延非线性火线随坡度的变化规律。发现了沟槽火前锋附着的临界条件，阐释了火焰附着前后对流传热机制的变化规律，揭示出燃料预热由辐射加热主导、逐渐转换为辐射加热和对流加热共同控制，揭示了火焰附壁后诱发爆发火的物理机理，建立了火蔓延速率与空气流速的无量纲关系式。揭示了峡谷火蔓延火线轮廓随坡度角的演化规律，揭示了高坡度条件下对流加热的热反馈是诱发爆发火的物理机制。项目可为爆发火预警方法的建立提供可靠的科学依据。. 项目总计发表论文13篇，博士学位论文5篇，硕士学位论文2篇。发表论文被SCI收录9篇，SCI高区论文5篇，其中在国际燃烧两大权威期刊Proceedings of the Combustion Institute和Combustion and Flame发表论文3篇。项目负责人应邀9次在本领域重要国际和国内学术会议作关于本项目研究成果的大会特邀报告。项目负责人获国家杰出青年科学基金，享受国务院政府特殊津贴，并入选国家百千万人才工程、第二批国家“万人计划”领军人才。项目负责人当选国际燃烧学会会士（国际燃烧学会正式设立的终身荣誉，用于表彰全球范围内在燃烧研究领域做出突出贡献的杰出科学家）、国际森林火灾学会理事、第37届国际燃烧会议Fire Research”主题主席等重要学术职务。