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W5E22 MEASUREMENTOFA3・DFLOW(GASANDLIQUID) STRUCTUREGENERATEDBYASPREADll河G FLAMEQVERn-BuTANE
G.Tashtoush1)，T.Ko凶shi2)，A.Ito2)，K.8aito1)andC.J.Cremers1)
(l)Department01MechanicalEnginering University01Kentucか Lexington，KY40506・0108
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(2)Depar仰 ent01Production砂'stemsEnginering OitaUniversity Oita870-1Japan
ABSTRACT
Flamespreadoverliquidsisofcurentinterestbecauseofitsimportancetofiresafety andthecuriosityofcombustionresearchersstudyingthefundamentalheat仕 組sfer mechanismofthisphenomenon.Themajorheat-仕 組sferprocesbetwentheflame's leadingedgeandtheliquidisahighly仕 組sientphenomenoninvolvingbothliquidand gasphases.百leseinteractwitheachotherthroughtheexchangesofmomentum，heat， andmas.Thecritical仕 組sportofthosequantitiesinthegasandliquidphωesocursln severalmilimeters仕omtheinterfaceandwithinafewcentimeters企omtheflame's leadingedge.Toimproveourunderstandingofthemechanismofflamespreadover liquidfuels，wedevelopedalasershetparticletrackingflowvisualization(L8PT) technique.LSPTisespecialydesignedforasimultaneousmeru写urementof3・Dflow structuresboththeliquidandthegasphasesaheadoftheflame.Thretraywidths(5，10， and20mm)anda1mmthick1節 目 shetwereused.TheLSPTsystemrevealeda transient2・Dprofileofflameinducedflowinboththegasandliquidphases. We measuredaseriesofveIocityprofilesinapulsatingflamespreadovern-butanolat
dif ferentdistancesbetwe enth~ liquidsurfaceandthelasershe et. Thisenabledustogeta 3-Dflowvisualizationinbothphases.Twinvorticesaheadoftheflamewereobservedin bothphases.Howeverthisflowgradualydisapearedwithincreasingdepthofthe liquid.TheLSPTalsoconfirmedtheexistenceoftwinvortices'flowontheliquid surfaceandintheliquidphaseafewm mbelowthesurface.Asimilartwinvortex structureinthegasphasewasalsoobservedforthefirsttime.百leseresultsprovedthat theconvectiveflowinbothliquidandgasphasesis3-Dinnatureinthe'thretrayswe used.
W ・ 1-P Poster Ses sion: Fire and Fire Sup pres sion Page489
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