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 sourcesin a parallel configurationand from 3 and 4 circular pools in a symmetrical cofiguration were studiimentally andtheoretically. Two kinds of fuel, propane and hexane适用于那些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 dimensionlessspeparation distance between the fire sourcesas 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/pc_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 firesources. And f_s And f_1 are the correction factors of apparent burning area to fire area And aredefined 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）/ (DW+S^2) for line/rectangular fire sources，Where n is number of pool fire sources，D width of shorter length of rectangular burner or characteristic length of pool fire sourceW width of longer length of rectangular burner，S - separation between fire sources. The same correction was obtained on flame extension behavior whena rectangular or a circular fire sources approaches to the wall if we consider an imaginary firesource 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.