Influence of sidewall restriction on flame characteristics of double fires in a channel

In this paper, the influences of sidewall restriction on flame characteristics of double fires in a channel were studied. Two typical fire scenarios (center fire and wall fire), different heat release rates and burner separation distances were considered. The results show that Delta T = 300 K can be used as the boundary temperature of the flame. Further, the merging phenomenon is more likely to occur for wall fires, and the critical flame merging separation distances (S-c) of center and wall fires are around 0.13 similar to 0.16 and 0.21, respectively. The flame tilt angle decreases with the increasing fire separation distance, and it is not sensitive to HRR for both center and wall fires. The flame tilt angle of wall fire is slightly larger than that of center fire under a given fire separation distance. Finally, two prediction models are proposed to estimate the normalized effective flame lengths of impinging and non-impinging flames for the center and wall fires in a channel. This study will provide a basis for exploring the interaction mechanisms of double fires under restricted boundary conditions.