SGER: Auto-ignition of Wood

项目摘要：木材的自动着火这是一项探索性研究的小额资助。建立了木材自燃的数学模型，并进行了数值求解。该模型考虑了固相和气相的物理和化学过程。在固-气界面边界条件中考虑了焦炭表面的氧化，当进入固体表面的热流密度较低时，焦炭表面的氧化是很重要的。该数值代码可以再现自燃的实验结果，并最终可以解释控制木材自燃的潜在物理和化学过程。自燃是火灾蔓延和发展的重要机制。它具有根本的利益，但它的复杂性阻碍了对控制它的重要机制的明确研究。虽然这项研究的重点是木材，但所建议的建模也可以涉及其他炭化和非炭化固体。木材在氧气气氛中的加热会导致原始材料的放热表面氧化和热分解。阴燃着火可能发生在表面，也可能发生火焰着火。这两种点火形式以前在自燃过程中没有区分。更广泛的影响这项基础性工作对公众和基础设施的整体安全非常重要。值得注意的是，它包含了在森林火灾中传播的问题，因为这种传播涉及离散的木质材料的辐射加热，导致氧化和燃烧。从教育的角度来看，这项工作的成果以独特的方案传递给消防工程专业的学生。这一成果将是解决表面和气相点火过程的第一个此类成果，并对公共安全和森林和建筑物中的火灾蔓延具有重要意义。

Project Summary: Auto-ignition of woodThis is a Small Grant for Exploratory Research. A model for autoignition of wood is developed and solved numerically. The model considers physical and chemical processes in both solid and gas phases. The char surface oxidation, important when the incident heat flux to the solid surface is low, is included in the solid-gas interface boundary conditions. The numerical code can reproduce the experimental results for autoignition and ultimately can explain the underlying physical and chemical processes governing the autoignition of wood. Auto-ignition is a significant mechanism in the spread and growth of fire. It is of fundamental interest, but its complexity has prevented a definitive study of the important mechanisms that control it. Although the focus of this study is wood, the proposed modeling can relate to other charring and non-charring solids as well. The heating of wood in an oxygen atmosphere leads to exothermic surface oxidation and thermal decomposition of the virgin material. Smoldering ignition can occur at the surface, and flaming ignition is also possible. These two forms of ignition have not previously been distinguished in the process of autoignition. Broader ImpactThis fundamental work is important to the overall safety of the public and infrastruture. Significantly, it embraces the problem of spread in forest fires since this spread involves the radiant heating of discrete woody material causing oxidation and flaming. From an educational point of view, the results of this work are transmitted to fire-protection engineering students in a unique program. This result will be the first of its kind in addressing both the surface and gas-phase ignition processes, and is significant to public safety and the spread of fire in forests and structures.