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Step[a]
Srep(b]
Step[c]
Step[d]
FIG.1.GasandliquidflowstructuresidentifiedbyLSPTandSTtechniquesforfourdiferentstepsofpulsatingflame spreadovern-propanolina2cmwideむay.The1eftcolumnis出etopviewofgas-phaseflowatandles出血 2mm fromthefuelsurface.Therightcolumnisthesideview.Tf=i凶世aliquidtemperほureandTfp =日ashpoint(23OC).
FIRE-Igni世onandFlameSpread
Topviev(x司 yp!ane，z=2mm) Sideview(Jトzplane)
Step[bJ:FormationofColdTempera如 何 Valey
Intheliquidphase，athermocapilaryflowtoward theupstreamdirectionisinducedbythetempera- turediferencebetweenthehotliquidunderthe flameandcoldliquidfar企omtheflame.Theliquid convectionflowisalsogeneratedinsidethebulkliq- uidat1to4m munderthefuelsurfacewherethe
temperatureisthesameastheinitialfueltempera司 ture.Asaresult，aliquidcirculationwasgenerated asshowninFig.1，Step[bJ.Inthegasphase，a5 m mlongand2m mwidecirculationcelwhosecen- terislocatedap proximately5m maheadoftheflame leadingedgeisformed(Fig.1，Step[b]).Thesurface temperatureprofile(Fig.2，top)showsthatthecold