Experimental And Theory Study On Vertical Combustion Characteristics Of Thermal Thin Material With Two Faces Exposed To Air

A spate of serious fire accidents of vertical burning combustibles has taken place in ourcountry in recent years,which caused tremendous damage to people’s lives and property.Vertical flame spread characteristics of thermal thin materials become new re-search.researchers often focused on burning of multi-adherent wood and ignition characteris-tics of fuel in different conditions,but quantitative analysis and theoretical research of verticalflame spread characteristics of thermal thin materials are not deep enough,especially for thethermal thin materials with two faces exposed to air.Research of thermal thin materials can’tmeet needs of the theory and fire protection design and technology of modern largespace,special functions or special shape building.In order to research the vertical flame spread characteristics of thermal thin materialswith two faces exposed to air and fill up the blank of this area,a physical mathematical modelof the vertical flame spread of thermal thin materials with two faces exposed to air was estab-lished on the basis of fire spread traces of burning combustible material after existing studiesthis paper and also experiments of the vertical fire spread of thermal thin materials with twofaces exposed to air were designed.Eight different sets of experiments of vertical flame spreadof middle size thermal thin materials with two faces exposed to air were carried out to verifyaccuracy of physical mathematical model.Numerical calculation model of vertical flamespread of thermal thin materials was established by software Simtec according to related pa-rameters of experiments of vertical combustion of thin material. Numerical simulation methodof vertical the vertical flame spread of thermal thin materials with two faces exposed to airwas explored.Results are as fol1ows:After cotton thin material was ignited,ignition source was removed immediately com-bustion of thin material can be self-sustaining.during the course, slight curl happened on thelower end of the specimen.Acceleration of fire spread gradually increased in the vertical di-rection.Speed of vertical fire spread was much faster than the horizontal one.Flame bodyturned into V-shaped prism from the inverted V-shape until the sample was devided into twoparts.For the plastic thin material,even though it can self-sustain burned.the speed showed rel-atively slow and falme body is small.Flaming droplets were produced during combus-tion.Flame spread unregularly.Decorative light cloth,advertising cloth of shopping malls,clothprojection can not be ignited.They can not achieve continued burning.Function of mass loss rate,the flame front position,vertical flame spread speed,the flamespread acceleration was fitted with the software orign8.5.1.The function can be expressed as a power function of time after ignition.The physical mathematical model of the vertical flamespread of thermal thin materials with two faces exposed to air was proved to be viable andcorrect by experiments of vertical flame spread of middle size thermal thin materials.Functionof vertical flame spread acceleration over time is.Maximum surface temperature of thin material numerically calculated by Simtec soft-ware was950℃,11%higher than the experimental result with850℃.Results were con-sistent with the experimental results. What’s more,the function of vertical flame spread accel-eration was a2f(t)0.644(t9)0.00121/(0.00570.341)(t9)1.659.Combustion processof the vertical flame spread of thermal thin materials with two faces reappears by usingSimtec software which was consistent with the experimental results.the software is suitablefor simulation of the vertical flame spread of thermal thin materials with two faces.