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mechanismsandnecesityofunderstandingthephenomenonanditsimpactonfiresafetyin liquid-storagetanksandacidentalspils:oflamable(e.g.，crudeoilandjet白め liquids.Inthe flamespreadoverliquids，liquidconvectionaheadofaflamespreadingoverliquidsisunique andplaysanimportantroleinthespreadingproces. Becauseofthepresenceofliquid convection，theflamespreadingprocesiscomplexincomparisontotheflamespreadover solids[3，4].
Inourpaststudies[1ム5]，wefocusedonobtainingacurateanddetai1edmeasurementsofflow (both liquid and gas)， tempera旬 re (both liquid and gas) and gaseous fu.el concen仕 ations generatedbythespreadingflame. Theflamespreadphenomenonishigh1ytransient，involving bothliquidandgasphasesthatinteractwitheachotherthroughtheexchangesofmomentum， heat，andmass，andthecriticaltransportofthosequant江iesthば ocurinthegasand1iquid phaseswithinseveralmilimetersofitsinterfaceandafewcentimetersups仕e紅 n企omthe flame'sleadingedge. Researchershaveapliedopticalmeasurementtechniquestorevealflow， tempera加reandfuelconcen廿ationdis仕ibution. Thremajorefortshavebenmaderecently: (l)NASAapliedarainbowschlierentovisualizetheliquidf10wandan旭丘町edcamerato measure the liquid-surface tempera旬 re [6，7]; (2) Castil lo et al. [8，9] ap plied a Sch1ieren technique to measure the liquid flow; and (3) in our laboratorywe ap p1ied holographic interferometry to visualize the 1iquid flow [10，1] and a dual wavelength holographic interferometrytomeasurefuelconcentrationsinthegasphase[1]. Inadition，NASA conductedasucesfulseriesofflame-spreadexperimentsovern-butanolundermicrogravity andprovidedvaluableexperimentaldata[12]thatrevealeda1:¥:¥札nvortexaheadof也e丑但ne's leadingedgeshowingthe3-Dnatureofthespreadphenomenon. Castiloeta.l[8]alsodeduced 企omtheirSch1ierenexperimentsthatthe也eoreticalpredictionsof.theflame-spreadingveloci句r tumouttobelargerthanthedirect1ymeasuredvalues.Theyconc1udedthatthy3-Dnatureofthe f10wisinducedbythetestsectionwalsthatretardandcolthewannliquidmovingaheadofthe 丑紅ne.
Despitethese五ndings，unfortunatelythecurentlyavailable(altheabovementioned)techniques areatbest2-D. Thus，weputtogetheranintemationalcolaborationamongtheUniversityof Kentucky，OitaU:出versl匂randKanagawaInstituteofTechnologytodevelopa3-Dmeasurement techniquewhichcanacuratelyandsimultaneouslymeasurethetransient3心 s廿ucturesoff1ow， tempera旬reandfue1concentration. Asthefirststeptowardthisintegratedmulti-measurement technique，wedevelopedalaser-shet-partic1e仕acking(LSPT)techniquethatc組 measurea transientthre-dimensiona1f10wdistributionofbothgasandliquidphasessimultaneously. We ap plied 出 is new LSPT to the flame spread tests over n-butanol because its flash point tempera加reisaboveroomtempera印re. Thusthecontrolofitssubflashpointtemperatureis r e l a t i v e l y e a s y . I n a d d i t i o n ， f l a m e s p r e a d o v e r b u t a n o l p o s s e s s e s a t y p i c a l f1 a m e s p r e a d c h a r a c t e r consist也g ofpulsating and unifon spread regions as a function ofthe initial butanol tempera旬re.