采用粒子图像测速来测量间隔区填充管道内液体和液体/气体流动液体速度场分布形态
Liquid andliquid/gasflowsthroughspacerfilledchannelswerestudiedusingParticleImagingVelocime-try (PIV)toprovideexperimentalsupportforvelocitydistributionsobtainedfromComputationalFluidDynamics studiesavailableintheliterature.ItisshownthatPIVisasuitabletechniqueformeasuringvelocity profilesinspacerfilledchannels,althoughcarehastobetakenwheninterpretingtheresults.PIV measurementswerecarriedoutforanentireflowcell(5cm×15 cm),asmallerareaofroughly7mm×8mmandforasinglespacercell(2.5mm×3 mm).Theexperimentalresultsshowthatfluidflowis welldistributedacrosstheentireflowcellinthecaseofsingle-phaseflow.Therecordingsofthesinglespacer cellshowedthatliquidflowismainlyparalleltothespacerfilamentsandthereforethedirec-tion offlowchanges90◦ over theheightofthechannel.Introductionofairbubblesintroducedstronglocal velocitygradients.Theliquidvelocityintwo-phaseflowsisshowntobemoreunsteadythaninthe caseofsingle-phaseflow,whichisadvantageouswhentryingtopreventfoulingorconcentrationpolarization.