简介：Themutualradiationimpedanceignoredinconventionalarraydirectivityformulaisintroducedintothecalculationofarrayradiationsoundfield,andamodifiedarraydirectivityformulaconsideringthemutualradiationimpedanceisgainedaccordingtothesuperpositionprinciple.Resultsofcomputersimulationandexperimentsforauniformlineararrayandauniformplanararrayshowsuperiorperformanceonthepresentofthepracticaldirectivitypatternofthemodifiedformulainthispaperincomparisontotheconventionalone.

简介：InordertoreconstructcomplicatedtemperaturefieldsmoreaccuratelybyacousticCT,areconstructionalgorithmbasedonMarkovradialbasisfunctionandTikhonovregularizationisproposedandnamedasMTRalgorithm.Withthealgorithm,theacousticvelocityfieldinamediumisapproximatedbyalinercombinationofMarkovradialbasisfunctions,theacoustictravel-timesovermulti-pathsandtheTikhonovregulationareusedtoreconstructtheacousticvelocitydistribution,andthenthetemperaturedistributioniscalculatedbyusingtherelationshipbetweenacousticvelocityandtemperature.Thetemperaturefieldmodelswithonehotspot,threehotspotsandfivehotspotsarereconstructedbyusingsimulationdata.ReconstructionresultsshowthattheMTRalgorithmcanreconstructthehottemperature,especiallythehotpositionaccurately.AnexperimentsystemfortemperaturedistributionmeasurementbyacousticCTisdeveloped.ThecapabilityofacousticCTtodetectahotspotcreatedbyelectricheatersinanexperimentalsilofilledwith1200kgsoybeansistestedbyusingtheMTRalgorithm.Inthereconstructiontemperaturefield,thehotpositioncanbedeterminedcorrectlyandthetemperatureerrorofthehotspotis1.3%.ItisthusclearthattheMTRalgorithmhasagoodcapacityofreconstructingcomplextemperaturefields,andcanbeexpectedtobeusedintemperaturemonitoringforactualstoredgains.

简介：

简介：Anewdual-fluidmodelconsideringphasetransitionandvelocityslipwasproposedinthispaperandtheCunninghamcorrectionwasusedinthedropletresistancecalculation.Thisdual-fluidmodelwasappliedtothenumericalsimulationsofwetsteamflowina2DLAVALnozzleandintheWhitecascaderespectively.Theresultsoftwosimulationsdemonstratethatthemodelisreliable.Meanwhile,thespontaneouscondensingflowinWhitecascadewasanalyzedanditinfersthattheirreversiblelosscausedbycondensationaccountsforthelargestshare(about8.78%ofinlettotalpressure)intotalpressurelosswhilethelosscausedbyvelocitysliptakesthesmallestshare(nearly0.42%),andanotherpartoftotalpressurelosscausedbypneumaticfactorscontributesalesssharethancondensation,i.e.almost3.95%ofinlettotalpressure.

简介：

简介：

简介：

简介：