Abstract :
Anapplicationofwire–meshsensorstoobtaintheinterfacialareaconcentrationinverticalpipesispresentedasanalternativetothewidelyusedmultiple-tipelectricaloropticalfibreprobes.Themeasuringdataofameshsensorconsistsofathree-dimensionalmatrixoflocalinstantaneousgasfractionsmeasuredateachcrossingpointofthewiresandrecordedasatimesequence.Bubblesareclearlydistinguishableinthisdatamatrix,sincetheyrepresentregionsofinterconnectedelementscontainingthegaseousphase.Themethodtodeducetheinterfacialareaconcentrationfromthisdataisbasedonafullreconstructionofthegas–liquidinterface,wheretheinterfacialareaofeachbubbleisrecoveredasthesumofthesurfaceareaofallsurfaceelementsbelongingtothegivenbubble.Thenewmethodcanbeappliedtolargebubbleswithanarbitraryshape.Tostudythechangeoftheinterfacialareaconcentrationalongthepipethedistancebetweensensorandgasinjectionwasvaried.Theaxialdevelopmentoftheinterfacialareadensitymeasuredinthetestpipeof195.3mminnerdiameterwascomparedtothemeasurementscarriedoutbySunetal.[Sun,X.,Smith,T.,Kim,S.,Ishii,M.,Uhle,J.,2002.Interfacialareaofbubblyflowinarelativelylargediameterpipe.Exp.ThermalFluidSci.27,97–109]inapipeof101.6mmdiameter,whichisthelargestpipeforwhichinterfacialareadensitiesarepresentedinliterature.Anacceptableagreementwasfound,whereasdeviationsareconsistentwiththedifferencesintheboundaryconditionsofbothexperiments.
