title: A quantitative model and the experimental evaluation of the liquid fuel layer for the downward flame spread of XPS foam.
abstract: The objective of this work is to investigate the distinctive mechanisms of downward flame spread for XPS foam. It was physically considered as a moving down of narrow pool fire instead of downward surface flame spread for normal solids. A method was developed to quantitatively analyze the accumulated liquid fuel based on the experimental measurement of locations of flame tips and burning rates. The results surprisingly showed that about 80% of the generated hot liquid fuel remained in the pool fire during a certain period. Most of the consumed solid XPS foam didn't really burn away but transformed as the liquid fuel in the downward moving pool fire, which might be an important promotion for the fast fire development. The results also indicated that the dripping propensity of the hot liquid fuel depends on the total amount of the hot liquid accumulated in the pool fire. The leading point of the flame front curve might be the breach of the accumulated hot liquid fuel if it is enough for dripping. Finally, it is suggested that horizontal noncombustible barriers for preventing the accumulation and dripping of liquid fuel are helpful for vertical confining of XPS fire.
authors.affiliation: State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, 230027, China.
authors.forename: Shengfeng
authors.initials: S
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, 230027, China. Electronic address: xqy@ustc.edu.cn.
authors.forename: Qiyuan
authors.initials: Q
authors.lastname: Xie
authors.affiliation: State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, 230027, China.
authors.forename: Xinyi
authors.initials: X
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, 230027, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Qiu
authors.affiliation: Shanghai Fire Research Institute of MPS, Shanghai, 200032, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Yang
keywords: Downward flame spread; Liquid fuel; Melting; Quantitative model; XPS foam