Upward flame spread on a flat surface, in a corner and between two parallel surfaces

Previous studies have demonstrated that upward flame spread on a flat surface is the 'worst' orientation for fire growth. Furthermore, upward flame spread in a corner and between two parallel surfaces are expected to lead to more rapid flame spread due to extra heat feedback and reduced air entrainment. Experiments were designed to study the fire behaviors of these geometries of wall fires, and samples used were 6 mm thick, 8 mm wide and 1 m tall PMMA slabs. Flame height, heat feedback to the unburned surface and flame spread rate were the parameters discussed. The corresponding observations found that the flame height correlation played an important role for flame spread for it differs among these three geometries. The influence of heat feedback was not crucial. In addition, the flame spread in a corner is the fastest while the difference of flame spread rate between the other two scenarios was not obvious. Therefore, for practical use, the prediction for wall fires on a flat surface can be inferred to the two parallel walls case.