Modeling and Experimental Study on Merging Flame from Multi-Fire Sources

Flame tip height which were showing merged form or inclined form from two rectangular fire sources in a parallel configuration，and from three and four circular pools in a symmetrical cofiguration were studied experimentally and theoretically.Two kinds of fuel，propane and hexane，were utilized for those fires respectively。Flame tip height in dimensionless form，L/L_m(where L and L_m are flame tip height and merged/inclined flame tip height without separation，respectively)，was expressed successfully by a function of dimensionless hear release rate and dimensionless speparation distance between the fire sources，as in the form of L/L_m=(Q^&lt；**&gt；_m·f_s)^&lt；2/5&gt；for square or circular pool fires and L_m&lt；2/3&gt；for rectangular or line fire sources.Q^&lt；**&gt；_m is defined as Q^&lt；**&gt；_m=Q/p·C_p·T_o·ROO&lt；gD&gt；·D^2for square/circular po ol fires，and Q^&lt；**&gt；_m=Q/p·C_p·T_o·ROO&lt；gD&gt；·DW for rectangular/fine fires without separation between fire sources.And f_s and f_1 are the correction factors of apparent burning area to fire area and are defined as f_s=(S^2+n·D^2)/n·(S^2+D^2)for square/circular fire sources and as f_1=(WD+S^2)/2·(DW+S^2)for line/rectangular fire sources，respectively.Where n is number of pool fire sources，D width of shorter length of rectangular burner or characteristic length of pool fire source，W width of longer length of rectangular burner，S separation between fire sources.The same correction was obtained on flame extension behavior when a rectangular or a circular fire sources approaches to the wall if we consider an imaginary fire source of the same size and in the same heat release inside a wall.

Flame tip height which were showing merged form or inclined form from two rectangular fire sources in a parallel configuration, and from three and four circular pools in a symmetrical cofiguration were studied experimentally and theoretically. Two kinds of fuel, propane and hexane, were utilized for those fires respectively. Flame tip height in dimensionless form, L/L_m (where L and L_m are flame tip height and merged / inclined flame tip height without separation, respectively), was expressed successfully by a function of dimensionless hear release rate and dimensionless speparation distance between the fire sources, as in the form of L/L_m = (Q^<**>_m・f_s) ^<2/5> for square or circular pool fires and L/L_m = (Q^<**>_m・ f_1) ^<2/3> for rectangular or line fire sources. Q^<**>_m is defined as Q^<**>_m= Q/p ・ C_p・ T_o・ ROO<gD>・ D^2 for square/circular po ol fires, and Q^<**>_m= Q/p ・ C_p・ T_o・ ROO<gD>・ DW for rectangular/fine fires without separation between fire sources. And f_s and f_1 are the correction factors of apparent burning area to fire area and are defined as f_s = (S^2+n・ D^2)/n ・(S^2+D^2) for square/circular fire sources and as f_1 = (WD+S^2)/2・(DW+S^2) for line/rectangular fire sources, respectively. Where n is number of pool fire sources, D width of shorter length of rectangular burner or characteristic length of pool fire source, W width of longer length of rectangular burner, S separation between fire sources. The same correction was obtained on flame extension behavior when a rectangular or a circular fire sources approaches to the wall if we consider an imaginary fire source of the same size and in the same heat release inside a wall.