简介:TransitiontoTaylorvortexflowbetweentwoconicalcylinders,withtheinneronerotatingandtheouteronestationary,isstudiedbythenumericalmethodinthisarticle.ItisfoundthatthebasicflowbecomesunstablewithincreasingofReynoldsnumber(Re)aboveacertaincriticalvalueRec=117andwiththefurtherincreaseofRetoaboutRe=300,thefirststablevortexisformednearthetopoftheflowsystem.TheannulusisfilledwithsixpairsofvorticesataboutRe=800.Theseareconfirmedbyexperimentalobservations.Moreover,thelocalextremevaluesofpressureandvelocityarereachedattheadjacentlinesbetweenneighboringvorticesoratthemediumlinesoflargevortices.Thelocalminimumvaluesofvelocityandthelocalmaximumvaluesofpressurearereachedatthesamepoint,whereasthelocalmaximumvaluesofvelocityoftheflowareassumedatthepointofinflectionforpressure.
简介:Undertheeffectsofelectricfieldandchemicalreaction,theproblemofdispersionofaerosolsinapoorlyconductingfluidinachannelissolvedanalyticallyusingthemixturetheorytogetherwitharegularperturbationtechnique.Itisshownthattheaerosolsaredispersedrelativetoaplanemovingwiththemeanspeedofatmosphericfluidaswellasthemeanspeedofagglomerationofaerosolwitharelativediffusioncoefficient,calledtheTaylordispersioncoefficient.Thiscoefficientisnumericallycomputedandtheresultsrevealthatitincreaseswithanincreaseintheelectricnumber,butdecreaseswithincreasingporousparameter.Thephysicalexplanationsforthephenomenaaregiveninthisarticle.
简介:Inthispaper,theflowpatternsobservedinhorizontalCouette-Taylorflow(CTF)werecorrelatedusingdimensionlessnumbers.Theanalysisoftheresultsshowedthatthestructureoftheflowwasanoutcomeofinteractionbetweenfluidinertiarelatedtoaxialandrotationalflowsandgravitation.Therefore,theflowstructureswerecorrelatedusingaxialandangularReynoldsnumbers,andArchimedesnumberforthegivenvalueofgas-to-liquidflowratio.Finally,thecorrelationforthepredictionofthetransitiontotheflowregimeobservedathighrotationalspeedswasproposed.ThecomparisonwithexperimentscarriedoutintheverticalCTFfromtheliteratureshowedthatthiscorrelationcanalsobeusefulinthecaseofverticalflow.