摘要
以凹槽和凸台为研究对象,对具有局部构型的平板开展可燃特性研究,特别开展了火焰向下传播和熄灭实验.火焰传播分为两个阶段,初始阶段棱角处火焰传播速度比平面快,一段时间后,整个火焰锋面达到与棱角处火焰相同的传播速度.考虑棱角结构与圆柱表面火焰传播相似,将棱角等效成圆柱建立了火焰传播模型,可准确预测具有局部构型材料的火焰传播速度.棱角结构对可燃极限影响并不显著,局部最薄或最窄的尺度决定其极限氧气浓度.
The flammability characteristics of flat plates with grooved and convex part are studied,respectively.The downward flame spread and extinction experiments are carried out.The flame spread process can be divided into two stages.In the initial stage,the flame spread rate at the corner is higher than that on the two-dimensional flat plate.After a period of time,the entire flame front reaches the same spread rate as that at the corner.Due to the similarity between the edge structure and the way the flame spreads on the rod surface,the edge is taken as an equivalent to a rod,based on which a flame spread model is established.The model can be used to predict the flame spread rate of solid materials with a grooved or convex part accurately.The extinction experimental results show that the edge structure has no significant effect on the flammability limit,and the minimum thickness and width of solid materials determine their limit oxygen concentration.
作者
吴传嘉
朱凤
王双峰
Wu Chuanjia;Zhu Feng;Wang Shuangfeng(Key Laboratory of Microgravity,Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190,China;School of Engineering Science,University of Chinese Academy of Sciences,Beijing 100049,China;State Key Laboratory of High-Temperature Gas Dynamics,Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190,China)
出处
《燃烧科学与技术》
CAS
CSCD
北大核心
2023年第6期653-659,共7页
Journal of Combustion Science and Technology
基金
国家重点研发计划资助项目(2021YFA0716203)
中国科学技术大学火灾科学国家重点实验室开放课题资助项目(HZ2021-KF12).
关键词
材料构型
火焰传播
可燃极限
等效圆柱
geometry configuration
flame spread
flammability limits
equivalent rod
