Experimental and theoretical analysis on lateral flame spread over inclined PMMA surface

The work in this paper aims to clarify the effect of angle on the lateral flame spread over inclined surfaces. PMMA slabs with width ranged from 2.5 cm to 12 cm were tested at the angles from 0° to 75°. Burning rate, flame spread rate, flame appearance and radiant heat flux were investigated experimentally and theoretically. The results suggest that in the cases of narrow PMMA slabs (less than 8 cm), the flame spread rate is in proportion to the square root of angle sine as Vf∝sin1/1θ. For wider slabs, the spread rate is higher than the theoretical result owing to enhanced radiant heat feedback. Pyrolysis length follows a power-law increase with the sample width, and the exponent approximates 0.48. Flame length is independent of the inclination angle, but also a power function of sample width.