Experimental Studies on the Effects of Spacing on Upward Flame Spread over Thin PMMA

详细信息    查看全文

• 作者：Hui Zhu ; Guoqing Zhu ; Yunji Gao ; Guoxiang Zhao
• 关键词：Spacing between wall and fuels ; Upward flame spread ; Flame height ; Pyrolysis spread rate ; Thermally thin PMMA
• 刊名：Fire Technology
• 出版年：2017
• 出版时间：March 2017
• 年：2017
• 卷：53
• 期：2
• 页码：673-693
• 全文大小：
• 刊物类别：Engineering
• 刊物主题：Civil Engineering; Classical Mechanics; Characterization and Evaluation of Materials; Physics, general;
• 出版者：Springer US
• ISSN：1572-8099
• 卷排序：53

文摘

Experiments were carried out to study the effect of spacing between wall and thin fuels on upward flame spread. The front flame height, back flame height, pyrolysis height, burnout length, and pyrolysis spread rate were measured by video image analysis with spacings of 2 mm, 7 mm, 13 mm, 19 mm, and 25 mm. Experiments were performed on uniform PMMA (polymethyl-methacrylate) samples with 200 mm height, 50 mm width, and 1 mm thickness. The results are as follows: (1) As the spacing increased, the front flame height, back flame height, pyrolysis height, and burnout length showed the same trajectory, first increased and then decreased. The maximum trajectory was observed at a spacing of 6.5% of the wall height. (2) At an infinite length of PMMA, the pyrolysis zone and pyrolysis spread rate would reach an asymptotic steady state, and the pyrolysis and burnout spread rates will be asymptotically equal. (3) Of particular interest is the maximum mass-loss rate for a wall spacing/sample height ratio (0.065) due to enhanced the radiation fluxes. In this study, the effects of spacing between wall and fuels on upward flame spread was investigated for the first time using 1 mm thick PMMA sheets, including two-face burning case.