Numerical analysis of flame merging characteristics of multiple fire sources

Abstract: This paper provides a numerical analysis of flame behaviours in multiple fires arranged in a square pattern, with a specific focus on temperature and flame merging dynamics. The study uses Fire Dynamics Simulator (FDS), an open-source Computational Fluid Dynamics (CFD) software that utilizes Large Eddy Simulation (LES) for low-speed flows, with a focus on heat transport from fires. The accuracy of the numerical data has been verified by comparing it with the centreline temperature derived from an experimental study. This research systematically analysed the effects of various parameters-such as the fire intensity of each burner and the separation distance within the burner array-on thermal behaviours and flame merging dynamics to understand their impact on the centreline temperature and flame height. The findings of this study provide valuable insights into how multiple fire sources interact and affect thermal profiles and flaming behaviours. The results generally showed that as the intensity of the fire increased while keeping the separation distance constant, both the centreline temperature and flame heights increased proportionally. Additionally, when the separation distance between burners was reduced, a noticeable increase in centreline temperature and flame height was observed. This effect was attributed to the increased merging of flames from the closely positioned burners. Keywords: Thermal characteristic, Flame merging, Fire array, Fire intensity, Separation distance