Study on accelerated flame spread behavior over PMMA plates under different inclination angles and material widths

doi:10.16265/j.cnki.issn1003-3033.2026.07.0811

Abstract

Abstract:

To reveal the effects of inclination angle (θ) and material width (W) on the acceleration behavior of solid flame spread, this study investigated the critical conditions for acceleration in solid flame spread using PMMA plates as fuel samples. Controlled experiments were designed with varying θ (0-45°) and W (25-150 mm). The results demonstrate that flame length progressively increases with both θ and W. The dimensionless flame spread rate exhibits a good exponential relationship with sinθ, and the proposed semi-empirical model can characterize the coupled effects of θ and W. The study reveals that flame spread transitions from a stable regime to an accelerated regime as θ and W increase, with the critical Θ value approaching 1 under flame acceleration conditions. A power-law relationship is observed between the mass loss rate and the characteristic combustion zone length (l_c), and the power exponent first increases and then decreases with θ. Concurrently, the dominant heat transfer mode shifts from radiation to convection with increasing θ.

Key words: inclination angle, material width, flame spread rate, polymethyl methacrylate (PMMA), accelerated spread, mass loss rate

CLC Number:

X932爆炸安全与防火、防爆

Fan Chuangang, Rao Guanjie, Bu Rongwei. Study on accelerated flame spread behavior over PMMA plates under different inclination angles and material widths[J]. China Safety Science Journal, 2026, 36(7): 53-59.

Figures/Tables 12

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试验工况	θ/(°)	W/mm
1~6	0	25、50、75、100、125、150
7~12	7.5	25、50、75、100、125、150
13~18	15.0	25、50、75、100、125、150
19~24	22.5	25、50、75、100、125、150
25~30	30.0	25、50、75、100、125、150
31~36	37.5	25、50、75、100、125、150
37~42	45.0	25、50、75、100、125、150