简介:Trajectoriesofflyinghotparticleswerepredictedinthiswork,andthetemperaturesduringthemovementwerealsocalculated.Oncetheparticletemperaturedecreasedtothecriticaltemperatureforahotparticletoignitebuildinginsulationmaterials,whichwaspredictedbyhot-spotignitiontheory,thedistanceparticletraveledwasdeterminedastheminimumsafetydistanceforpreventingtheignitionofbuildinginsulationmaterialsbyhotparticles.Theresultsshowedthatforspherealuminumparticleswiththesameinitialvelocitiesanddiameters,thehorizontalandverticaldistancestraveledbyparticleswithhigherinitialtemperatureswerehigher.Smallerparticlestraveledfartherwhenotherconditionswerethesame.Thecriticaltemperatureforanaluminumparticletoigniterigidpolyurethanefoamincreasedrapidlywiththedecreaseofparticlediameter.Thehorizontalandverticalsafetydistanceswerecloselyrelatedtotheinitialtemperature,diameterandinitialvelocityofparticles.Theseresultscouldhelpupdatethesafetyprovisionoffireworkdisplay.
简介:Spreadoffiresmokeintheelevatorshaftofahigh-risebuildingisinfluencedbymanydrivingfacts.Wesimulatesmokespreadingintheelevatorshaft,stairroom,andpre-chamberwithandwithoutdifferentsuppliedpressurizedair.Thesimulationshowsthatsmokemovesveryfastintheelevatorshaft.Whena12floorhigh-risebuildingisinfire,smokecanfilluptheelevatorshaftinlessthan1.5minafterafirestarted,temperatureintheelevatorshaftcanbehigherthan187?Cin5min,andtheconcentrationofCOcanalsoreachahighlevel.Theelevatorshafthasaverylowvisibilityinlessthanabout100s.