外文资料--Numerical Simulation Method of Acoustic Field Positive Problem based on Magnetoacoustic Tomography with Magnetic Induction.PDF外文资料--Numerical Simulation Method of Acoustic Field Positive Problem based on Magnetoacoustic Tomography with Magnetic Induction.PDF

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NUMERICALSIMULATIONMETHODOFACOUSTICFIELDPOSITIVEPROBLEMBASEDONMAGNETOACOUSTICTOMOGRAPHYWITHMAGNETICINDUCTIONHUIXIA1,GUOQIANGLIU1,YANHONGLI1,YANGZHANG1,SHIQIANGLI1ANDLAIFUZHANG21INSTITUTEOFELECTRICALENGINEERING,CHINESEACADEMYOFSCIENCESBEIJING,CHINA2SHANXIELECTRICPOWERRESEARCHINSTITUTESHANXI,CHINAXIAHUIMAILIEEACCNABSTRACTMAGNETOACOUSTICIMPEDANCETOMOGRAPHYWITHMAGNETICINDUCTIONMATMIISANEWIMAGINGMETHODITSIMAGESREFLECTCONDUCTIVITYDISTRIBUTIONINTHISPAPER,WEFIRSTLYPROPOSEDTHENUMERICALSIMULATIONMETHODOFMULTIPHYSICSFIELDSCOUPLINGTOOBTAINTHEDISTRIBUTIONOFACOUSTICFIELDINMATMIWITHOUTTHESTATICMAGNETICFIELDSIMPLEACOUSTICDETECTIONEXPERIMENTSARECONDUCTEDTOVALIDATETHEALGORITHMTHERESULTSDEMONSTRATEDITSFEASIBILITY,ANDMAYPROVIDESOMETHEORETICALFOUNDATIONFORTHEFURTHERRESEARCHONTHEREALTIMEDETECTIONOFACOUSTICSIGNALSANDTHERECONSTRUCTIONMETHODOFTHEMATMIKEYWORDSMAGNETOACOUSTICTOMOGRAPHYWITHMAGNETICINDUCTIONMATMI,MULTIPHYSICSFIELDSCOUPLING,TWODIMENSIONALAXISYMMETRICMODEL,NUMERICALSIMULATIONOFACOUSTICFIELDIINTRODUCTIONASAKINDOFFUNCTIONALIMAGING,ELECTRICALIMPEDANCETOMOGRAPHYEITHASMANYPREDOMINANCECOMPAREDWITHCONVENTIONALIMAGINGMEANS,SUCHASNONINVASIVEDIAGNOSE,HIGHIMAGINGQUALITYANDSOONBUTEITHASNOTBEENUSEDINCLINICALAPPLICATIONBECAUSEOFIT’SLOWRESOLUTIONNOW13INORDERTORESOLVETHEPROBLEM,MAGNETOACOUSTICTOMOGRAPHYWITHMAGNETICINDUCTIONMATMIISPROPOSEDBYBINHEETAL4,WHICHISSHOWNINFIG1INMATMI,IMAGINGTARGETISPLACEDINASTATICMAGNETICFIELDWITHPULSEDMAGNETICSTIMULATIONIMPOSEDONIT,THEPULSEDCURRENTINDUCESEDDYCURRENTINTHESAMPLE,ANDTHEINDUCEDEDDYCURRENTINSTATICMAGNETICFIELDGENERATESLORENTZFORCETHELORENTZFORCECAUSESACOUSTICVIBRATION,ANDTHEGENERATEDACOUSTICWAVECANBEMEASUREDAROUNDTHESAMPLETORECONSTRUCTTHECONDUCTIVITYDISTRIBUTIONOFTHESAMPLEFIGURE1THEILLUSTRATIONOFMATMIQUOTEDFROM4ONTHEBASISOFTHEPRINCIPLEMENTIONEDABOVE,WEPROPOSEANEWNONSTATICMAGNETMATMIMETHODINTHISPAPER,WEANALYZETHEPRINCIPLESOFMULTIPHYSICSFIELDSCOUPLING,INCLUDINGTHETWODIMENSIONALAXISYMMETRICTRANSIENTELECTROMAGNETICFIELD,DISPLACEMENTFIELD,SOUNDFIELD,ANDPUTFORWARDTHEMETHODOFMULTIPHYSICSCALCULATIONSONTHEBASICOFABOVEALL,THEFORMULAFORCALCULATINGTHEVARIOUSFIELDSAREDERIVEDINDETAIL,ANDCONDUCTTHESIMPLEACOUSTICDETECTIONEXPERIMENTSTOVALIDATETHEMETHODIITHENUMERICALSIMULATIONMETHODOFMULTIPHYSICSFIELDSCOUPLINGTHEMETHODADOPTSIMPULSINGPOWERSOURCEASTHEDRIVINGSOURCE,EXCITINGCOILGENERATESALTERNATINGELECTROMAGNETICFIELDWHICHEXCITESLORENTZFORCEINTHESAMPLETHELORENTZFORCECAUSESVIBRATIONOFSAMPLEBOUNDARY,THENACOUSTICWAVESISEXCITEDINTHEAIRWECANINVERSETHESAMPLERESISTIVITYBYDETECTINGACOUSTICWAVESIGNALTHESOUNDFIELDDISTRIBUTIONOFTHESAMPLECANBESIMULATEDTHROUGHSOLVINGTHEMULTIPHYSICALEQUATIONWHICHINCLUDESELECTROMAGNETICEQUATION,WIENEREQUATIONOFELASTICSOLIDSANDSOUNDFIELDEQUATIONINTHEAIRATHEEQUATIONOFAXISYMMETRICELECTROMAGNETICFIELDSTHEEXCITINGCOILISHOLLOWCYLINDRICALCOIL,ANDROUNDCOPPERSHEETISSELECTEDASTHESAMPLE,THESIMULATIONMODELHASAXIALSYMMETRY,SOTHEVECTORMAGNETICPOTENTIALAKONLYHASCIRCUMFERENTIALCOMPONENT,LABELEDASA,THECORRESPONDINGAXISYMMETRICELECTROMAGNETICEQUATIONIS22S2A1AAAAJRRRRZT∂∂∂∂−−Σ−∂∂∂∂1WHEREISMAGNETICPERMEABILITY,ΣISELECTRICALCONDUCTIVITY,ANDSJISCURRENTDENSITYOFTHEEXCITINGCOILALTHOUGHTHECURRENTDENSITYOFTHEEXCITINGCOILGENERATESONLYCIRCUMFERENTIALCOMPONENT,MAGNETICFLUXDENSITYINCLUDESRADIALANDAXIALCOMPONENT,WECANGETAJT∂−Σ∂9781424447138/10/25002010IEEERABZ∂−∂ZAABRR∂∂2INORDERTOAVOIDTHESINGULARITYATTHEBOUNDARYWHICHREQUALSTOZERO,SOSUPPOSEUISTHERATIOOFAANDR,THENTHEEQ2BECOMES222SUUUUUR3RRRJRRZTT∂∂∂∂∂−Σ−Ε−∂∂∂∂∂3ONBOTHSIDESOFTHEEQ3AREMULTIPLIEDBY2R,WECANGET222323332SUUUUUR3RRRRJRRRZTT∂∂∂∂∂−Σ−Ε−∂∂∂∂∂4IFNOTETHERANDZFORXANDYRESPECTIVELY,WEGET233332S2UUUUXXXXJXXXYYTT⎛⎞∂∂∂∂∂∂⎛⎞−Σ−Ε−⎜⎟⎜⎟∂∂∂∂∂∂⎝⎠⎝⎠5FROMTHEEQ5,WECANSEE⎟⎟⎠⎞⎜⎜⎝⎛∂∂∂∂⎟⎠⎞⎜⎝⎛∂∂∂∂YUXYXUXX33ISTHE3UX∇⋅∇UNDERRECTANGULARCOORDINATESYSTEM,WECANGET23332S2UUXUXXJXTT∂∂∇∇−Σ−Ε−∂∂6ACCORDINGTOTHESOLVINGRANGEOFTHEFIG2A,WECANSEETHATΩ1ISTHEAIRRANGE,Ω2ISTHESAMPLEPOSITION,Ω3ISTHEEXCITINGCOILPOSITIONINTHEΩ1AREA,CONDUCTIVITYEQUALSZERO,ANDTHEREISNOEXCITINGSOURCEINTHEΩ2AREA,THEREISALSONOEXCITINGSOURCEINTHEΩ3AREA,THECURRENTINTHECOILISTHESOURCECURRENTTHENEQUATIONOFTHETHREESOLVINGAREASCANBEWROTERESPECTIVELY3XU0∇−∇7−133UXUX0T∂∇−∇Σ∂7−232SXUJX∇−∇7−3ATTHESYMMETRYAXISANDINFINITYBOUNDARY,THEBOUNDARYCONDITIONISTHATUEQUALSZEROSO,AFTEROBTAININGTHEU,SUBSTITUTINGRAU/INTOEQ1,WECANGETELECTRICFIELDINTENSITYANDMAGNETICFLUXDENSITYAUERTT∂∂−−∂∂,RUBRZ∂−∂,ZUBR2UR∂∂81Ω2Ω3Ω2Γ3Γ2Ω3Ω2Γ3Γ1Γ1Ω2Ω3Ω2Γ3ΓFIGURE2SOLVINGMODELS(AELECTROMAGNETICFIELDSOLVINGMODEL(BDISPLACEMENTFIELDSOLVINGMODEL(CSOUNDFIELDSOLVINGMODELBASEDONEQ8,WECANGETSFJBKKK9BAXISYMMETRICNAVIEREQUATIONSOFELASTICSOLIDSACORDINGTOTHETHEORYOFCONTINUUMMECHANICS,THEWIENEREQUATIONOFELASTICSOLIDCANBEDERIVEDTHROUGHUSINGMOMENTUMCONSERVATIONPRINCIPLE,LAWOFCONSERVATIONOFMASSANDCONSTITUTIVEEQUATIONOFMECHANICALPROPERTIESINANINERTIALREFERENCEFRAMETHEVECTORFORMOFTHEWIENEREQUATIONCANBEWROTEAS222UGGUUFT12V∂Ρ∇∇∇⋅∂−KKKK10WHEREUURZT,,KISDISPLACEMENTFIELD,FKISUNITVOLUMEFORCE,ΡISDENSITYOFCOPPERSHEET,GISSHEARMODULUS,ANDVISPOISSON’SRATIOUNDERTHECYLINDRICALCOORDINATES,EQ10CANBEWROTE22RRRR22UUGGUF12RRT∂∂Θ⎛⎞∇−Ρ⎜⎟−Ν∂∂⎝⎠10−122ZZZ2UGGUF12ZT∂∂Θ∇Ρ−Ν∂∂10−2RRZUUUURRZ∂∂Θ∇10−3WHERE2RU∇、2ZU∇、R∂Θ∂ANDZ∂Θ∂CANBEWROTE222RRRR22UUU1URZRR∂∂∂∇∂∂∂11−1222ZZZZ22UUU1URZRR∂∂∂∇∂∂∂11−2RZRR2UUUU1RRRZRRR∂∂∂∂Θ∂⎛⎞−⎜⎟∂∂∂∂∂⎝⎠11−3RZRUUU1ZZRZRZ∂∂∂∂Θ∂⎛⎞⎜⎟∂∂∂∂∂⎝⎠11−4INORDERTOVOIDTHESINGULARITYATTHEBOUNDARY,SUPPOSEORRUUR,ANDSUBSTITUTINGRORUUINTOEQ101,ANDONBOTHSIDESOFTHEEQUATIONMULTIPLIEDBYTHE2R,WECANGET22323OROROR22223ORZR22G1UUUR3RGR12RRZUUGRFR12RZT−Ν⎛⎞∂∂∂⎜⎟−Ν∂∂∂⎝⎠∂∂Ρ−Ν∂∂∂12THESOLVINGRANGEISSHOWNINFIGURE2B,THEBOUNDARYCONDITIONSCANBEWROTEATTHE2ΓAND3ΓSFNP−KK13WHERESNKISUNITNORMALVECTORWHICHPOINTINGTHEOUTSIDEOFTHESAMPLEORCOILCAXISYMMETRICACOUSTICWAVEEQUATIONINTHEEXPERIMENT,BECAUSETHEREISNOLORENTZFORCEINTHEAIR,THEACOUSTICWAVEEQUATIONINTHESOLVINGRANGEOFFIG2CCANBEWROTEAS222210PPCT∂∇−∂14INTHECYLINDRICALCOORDINATE,WECANGET2222222110∂∂∂∂−−−∂∂∂∂PPPPCTRRRZ15WHERETHEBOUNDARYCONDITIONISR0ATTHEAXISOFSYMMETRY,ANDP0ATTHEINFINITEPOINTONTHE2ΓAND3Γ,THEBOUNDARYCONDITIONAREASFOLLOWS,22UNPNT∂⋅∇⋅∂KK16ACCORDINGTOTHEEQ10EQ16,WECANSOLVETHESOUNDWAVEDISTRIBUTIONINTHESOUNDFIELDOFTHESAMPLEIIIEXPERIMENTSASIMULATIONEXPERIMENTINTHESIMULATIONPROCESS,THEWAVEFORMOFEXCITINGCURRENTCANBESHOWNASFOLLOW0SIN−TVITETLΑΩΩ17WHEREDISCHARGEVOLTAGE0V1000V,INDUCTIONL77ΜH,RESISTANCER806E3Ω,CAPACITYC200ΜF,ΑR/2L,21/LCΩΑ−INTHECOURSEOFPRACTICALAPPLICATION,THECURRENTWAVEFORMISINTERCEPTEDBYATHYRISTOR,ANDONLYRESERVESTHEFIRSTPOSITIVESPIKETHEIMPULSEWIDTHISABOUT120ΜS,NUMERICALSIMULATIONRESULTOFSOUNDFIELDDISTRIBUTIONAT60ΜSISSHOWNBELOWINFIG3FIGURE3AATTHETIMEOF60ΜS,SOUNDFIELDDISTRIBUTIONOFTHEEXCITINGCOILITSELFFIGURE3BATTHETIMEOF60ΜS,SOUNDFIELDDISTRIBUTIONOFTHESAMPLEFROMTHEFIG3A,WEFINDTHATTHESOUNDFIELDDISTRIBUTIONOFEXCITINGCOILCANBEAPPROXIMATELYCONSIDEREDASACIRCULARRINGWHOSECENTERISTHECOIL’STHEINSIDEANDOUTSIDEBOUNDARIES,ANDATTHESYMMETRYAXIS,THESOUNDFIELDISTHESTRONGESTATTHESAMETIME,WEFIND,INTHEDISPLACEMENTY0,THEACOUSTICSIGNALSTRENGTHGENERATEDBYCOILITSELFISWEAK,ITCANBESHIELDEDBYMEANSOFSOMEMEASURESTHATCANEFFECTIVELYELIMINATETHEINFLUENCEOFACOUSTICSIGNALGENERATEDBYTHECOILITSELF00000000000300000600000900001225000020000015000010000050000050000100000150000SIGNALINTENSITY/AUTIME/S000050001000200050008001FIGURE4AATX0,THESIMULATIONACOUSTICSIGNAL0000000000030000060000090000122000001000000100000SIGNALINTENSITY/AUTIME/S00000500020005001015FIGURE4BATY00005,THESIMULATIONACOUSTICSIGNALINFIG3B,WECANSEETHATSOUNDFIELDDISTRIBUTIONCONCENTRATEAROUNDTHEAXISOFSYMMETRYINORDERTOFURTHERUNDERSTANDTHECHARACTERISTICSOFACOUSTICSIGNALS,WESELECTTHEDIFFERENTCOORDINATEPOINTSTOSIMULATETHEACOUSTICSIGNAL,ANDTHETIMESTEPSETTO10ΜSAFTERACHIEVINGTHEACOUSTICSIGNALOFTHEVARIOUSPOINT,THECONTINUOUS120ΜSDATAWERESEGMENTEDINTO01ΜSEPOCHSFORFFTTRANSFORMANDOBTAINTHESIGNALFREQUENCYINTHEAXISOFX0,WEOBTAINTHESIMULATIONACOUSTICSIGNALSHOWNINFIG4A,ANDINTHEAXISOFY00005M,WEOBTAINTHESIMULATIONACOUSTICSIGNALSHOWNINFIG4BAFTERANALYSISANDCALCULATION,WEFINDTHATTHEFREQUENCYOFACOUSTICWAVESIGNALMAINLYCONCENTRATEINTHERANGEOF35KHZINTHESPHERICALSOUNDFIELDRANGEWHOSECENTERISTHESAMPLE’SCENTERANDRADIUSISAPPROXIMATELY0005MBACOUSTICDETECTIONEXPERIMENTWEADOPTTHEEXPERIMENTALSYSTEMTODETECTTHESOUNDFIELDOFTHECOPPERSHEETSAMPLEWITHREGARDTOADETAILEDDESCRIPTIONOFTHEEXPERIMENTCANREFERTOLITERATURE5INTHESPHERICALSOUNDFIELDRANGEWHOSECENTERISTHESAMPLE’SCENTERANDTHERADIUSISAPPROXIMATELY0005M,THEACOUSTICSIGNALUNDEREXCITATIONISDETECTEDTHENWEPROCESSTHEDETECTEDSOUNDSIGNALBYFFT,ANDOBTAINSIGNALSPECTRUMTHEACOUSTICSIGNALOFMEASUREMENTPOINTTISSHOWNINFIG5FIGURE5DETECTEDACOUSTICWAVESIGNALANDIT’SSPECTRUMAFTERMULTIPOINTMEASUREMENTANDANALYSIS,WEFINDTHATTHEFREQUENCYOFDETECTEDSOUNDWAVESIGNALMAINLYCONCENTRATEINTHESPECTRUMRANGEOF35KHZ,ITISCONSISTENTWITHTHESIMULATIONRESULTSITPROVESTHATTHESIMULATIONMETHODOFMULTIPHYSICALFIELDCOUPLINGISCORRECT,THEMETHODOFMATMIISFEASIBLEIVCONCLUSIONMEDICALIMAGINGISARESEARCHDOMAINWITHBROADDEVELOPMENTPROSPECT,ITISESSENTIALTOTHEADVANCEMENTOFMEDICINEANDIMPROVEMENTOFPEOPLE’SLIFEINTHISPAPER,OURMETHODSHOWSTHATITISPOSSIBLETOCOMPLETETWODIMENSIONALAXISYMMETRICACOUSTICWAVEPOSITIONPROBLEMOFMATMIWITHOUTTHESTATICMAGNETICFIELDITCANBESEENASTHETHEORETICALREFERENCEFORTHEFUTURESTUDYONMATMIACKNOWLEDGEMENTSTHEAUTHORSTHANKTHENATIONALNATURALSCIENCECOUNCILOFCHINAFORFINANCIALSUPPORTGRANTNO60802086,50977084,FOUNDATIONOFCHINAPOSTDOCTORGRANTNO20090450570,BEIJINGNOVAPROGRAMGRANTNO2009B48ANDTHENATIONALHIGHTECHNOLOGYRESEARCHANDDEVELOPMENTCOUNCILOFCHINAGRANTNO2007AA06Z212REFERENCES1VCHEREPENINETALA3DELECTRICALIMPEDANCETOMOGRAPHYEITSYSTEMFORBREASTCANCERDETECTIONJ,PHYSIOLMEAS,2001221,9182JPMORUCCIANDBRIGAUDBIOELECTRICALIMPEDANCETECHNIQUESINMEDICINEPARTIIIIMPEDANCEIMAGINGTHIRDSECTIONMEDICALAPPLICATIONSJCRITREVBIOMEDENG,199624466556773ADSEAGAR,DCBARBER,BHBROWNTHEORETICALLIMITSTOSENSITIVITYANDRESOLUTIONINIMPEDANCEIMAGINGJCLINPHYSPHYSIOLMEAS,1987813314XYUAN,BHEMAGNETOACOUSTICTOMOGRAPHYWITHMAGNETICINDUCTIONMATMIJPHYSMEDBIOL,200550517551875HXIA,GLIUETALIMAGINGMETHODOFNEWMAGNETOACOUSTICIMPEDANCETOMOGRAPHYWITHMAGNETICINDUCTIONPROCEDINGSOFSECONDINTERNATIONALCONFERENCEONSPORTSSCIENCEANDSPORTSENGINEERINGSSSE2009,99103
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本文标题:外文资料--Numerical Simulation Method of Acoustic Field Positive Problem based on Magnetoacoustic Tomography with Magnetic Induction.PDF
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