Abstract
Experimental study on merged flame and plume was performed to clarify the fire plume merging phenomena and its behavior above two rectangular burners in parallel configuration. Measurements of temperature, upward velocity and CO2 concentration along the vertical centerline between burners were conducted by means of thermocouples, bidirectional tubes, and non-dispersed gas analyzer. Visible merged or inclined flame height was also measured by means of a video camera.
Two types of rectangular diffusion burners, the aspect ratio of which were 1:20 and 1:40 respectively, were employed in this study. These rectangular burners were placed in a quiescent atmospher, the separation distance between the burners varying from 0.05 to 0.30 m. Propane gas was used as a fuel and the heat release rate per unit was changed, ranging from 9.5 to 57.0 kW/m.
Fire plumes above each rectangular diffusion burner in parallel configuration merged above the centerline between burners, and formed a single merged plume in a higher region. The height at which the plumes started to merge was a function of the separation distance of two rectangular burners, being independent on the heat release rate. The height at which merging occurred could be deduced by separation distance. Moreover, the decaying slope for excess temperature and upward velocity behavior along the centerline between burners of the merged plume showed the same properties as a line fire source.
