Experimental And Numerical Simulation Of Multiful Sources Fire Whirlwind

Fire whirlwind is a special kind of fire phenomenon,which often occurs in natural environment such as forest fire,field fire and grassland fire,it also appears in the fire of urban buildings.Compared to the average fire,the fire whirlwind has great destructive power,the fire whirlwind burning rate are faster,the flame has a larger height to diameter ratio,the flame temperature and radiant heat greatly enhanced.During the fire,because of entrainment,the fire whirlwind will continue to suck the surrounding objects,and the burning debris are thrown into the distance,resulting in formation of flying fire,increasing the difficulty of fighting,threatening the personal safety of the firefighter.In the event of multiple fire whirlwinds in the fire,greater casualties and property damage can be created.Therefore,it is of great significance to study the combustion characteristics of multi-fires fire whirlwind.In this paper,an improved four-sided wall-slit experimental device was used to experimentally study the fire whirlwind of multiple fire sources.The quality of aviation kerosene with time curve was recorded by electronic balance and Matlab program to get the mass burning rate of quasi-steady-state fire whirlwind.The qualitative and quantitative analysis of the fuel quality shows that the fire whirl formed by the larger diameter oil pan is more susceptible to the drag force and the role of vorticity than the smaller one.The continuous flame image recorded by the camera was used to obtain the flame height.The flame height was qualitatively analyzed in the five stages of the fire whirlwind generation.Combined with the velocity circulation,the semi-empirical linear relationship between the mass burning rate and the flame height of the multi-fire sources fire whirlwind was analyzed.