磁流体微观结构的模拟与控制方法研究

E:2007375:707~715:2006-12-09(:50436020)*E-mail:[e-mail]*(,210094),,,.,,;,,,.(magneticfluid)(10nm),().,.,[1,2].,:.,,,(),,“”.[3],,,;,,.,,,,.,(MonteCarlo,MC)708E37(MolecularDynamics,MD).,Akira[4~6]“Cluster-Moving”MC,,;Castro[7],MC;[8],MC.Yoshihisa[9]MD,,;Akira[10]MDMD,.,,,,,:MC,;MD,LJ[9],LJ,;[10];[9,10],.,MD,,,,,,.11.1,.miju[11]hiu[1]riju[12]viju[13],:3203{3()()},4πpmijijiijjijijpdmurdµ⎛⎞=⋅⋅−⋅⋅⎜⎟⎜⎟⎝⎠nnntnt(1)0,hiiumHµ=−⋅nh(2)2π22ln,2pijijprijijdrrddurξδδ⎧⎫⎛⎞−⎪⎪=−−⎜⎟⎨⎬⎜⎟⎪⎪⎝⎠⎩⎭(3)()()2222422ln,6422vvvijvvvvLLAuLLLL⎧⎫+⎪⎪=−++⎨⎬+++⎪⎪⎩⎭(4)ij;0µ;pd;δ5:709;ijr;d,2pddδ=+;ξ;AHamaker;2/2vijpLrd=−;g;ρ∆;z∆;in,/iiim=nm,im,iim=m;ijt,/ijijijr=tr,ijij=−rrr,ijijr=r,ir;h,=h/HH,H=H.,:mλ=203,4πpmdkTµ(5)0,hmHkTµλ=(6)2π,2prdξλ=(7)mλ;hλ;rλ.k;T.[8],,.,,:()()()()()()3435,pmijmijijiijjijijjijiiijjijdkTrλ⎡⎤=−−⋅+⋅×⋅−⋅+⋅⎣⎦Fnntntnttntnntn(8)()0,hiiµ=⋅∇FmH(9)1ln,rijvijijdkTrλδ⎛⎞=⋅⎜⎟⎜⎟⎝⎠Ft(10)()()23216,24vijvvvALLL=+⋅+F(11),biCt=∆FG(12)34π,3giprgρ=∆F(13)()33,pmijmijjijiijijdkTrλ⎛⎞⎡⎤=−×−⋅×⎜⎟⎣⎦⎜⎟⎝⎠Tnnntnt(14)000.hiiimHmµµµ=×=×=×TnhnHmH(15)mijF,hiF,rijF,vijF,biFgiF710E37;6πcPBCdkTη=,t∆,G.mijThiT.mijFvijFijcrr,cr,;rijFpijdrd,.,,Z().1.2,,.[10],:()Stokes;();();().,[10]d1(),dmhrvgiijiijijittζ⎡⎤=++++⎣⎦∑rFFFFF(16)d1(),dmhiijiirtζ⎡⎤=+×⎣⎦∑nTTn(17)irin;tζrζ,3πtpdζη=,πrpdζη=,η.,x,y,z,cr=10pd.N,.,Euler,,.1.3L,N,η,φ.,,pd.,δ,ξ.,m,m.dt.:231.3810J/Kk−=×,7204π10NAµ−−=×⋅,300KT=,8d210st−=×,10nmpd=,ξ=18210/m,1.5nmδ=,0.1Pasη=⋅,A=9210Nm−×⋅,g=29.8m/s,()352401000kg/mρ∆=−.,mH,m19210Am−⋅,H510A/m.157rλ=,mλhλ(,mH).33π/(6)pNdLφ=,N,Lφ.N=400φ=0.01,5:71172.7510Lm−=×.,,φ0.005,0.01,0.020.04,N200,400,8001600.hλ=30,mλ=3,6,930;mλ=6,hλ=1,5,2040.N=400φ=0.01.22.11400N=,φ=0.01,157rλ=6mλ=,.1(a),,;1(b)~(d)410,5105510×.,,,,,,,,.1(a)Nstep=0;(b)Nstep=104;(c)Nstep=105;(d)Nstep=5105,.2,0.005,0.01,0.020.04,5510×.,,,,,,.,.,,712E37,,.2(a)φ=0.005;(b)φ=0.01;(c)φ=0.02;(d)φ=0.042.23(hλ=10).3(a)~(d)104,2×104,5×104105.,,.,3(a)(b),,;,3(c)(d),,,,.13,,,;,,,,.,,,.,,,,.4,105.4(a)~(d)0.005,0.01,0.020.04.,,,;,,.2.3λm530hλ=,φ=0.015:7133(a)Nstep=104;(b)Nstep=2×104;(c)Nstep=5×104;(d)Nstep=1054(a)φ=0.005;(b)φ=0.01;(c)φ=0.02;(d)φ=0.04.,,5(a),3mλ=,,,;,,,5(b)~(d);,5(c),9mλ=,,714E375(a)λm=3;(b)λm=6;(c)λm=9;(d)λm=30,“”;5(d)(30mλ=)5(c)(9mλ=),30mλ=9mλ=,9mλ=,.mλ,,mλ,“”,,MC[4].,,,.2.4hλ66mλ=,φ=0.01.,,6(a),1hλ=,,,,,,;5hλ=,6(b),,1hλ=,,;,6(c)(d),,,,,,.,,,,,.,.,,hλ,.5:7156(a)λh=1;(b)λh=5;(c)λh=20;(d)λh=403MD,,,;,,.,,,,;,,,,.1..,,20032RosensweigRE.Ferrohydrodynamics.Cambridge:CambridgeUniversityPress,19853LiQ,XuanY,WangJ.Experimentalinvestigationsontransportpropertiesofmagneticfluids.ExpThermFluidSci,2005,30(2):1091164AkiraS,ChantrellRW,Shin-IchiK,etal.Two-dimensionalMonteCarlosimulationstocapturethickchainlikeclustersofferromagneticparticlesincolloidaldispersions.JColloidInterfaceSci,1996,178(2):6206275SatohA,ChantrellRW,Shin-Ichi,etal.ThreedimensionMonteCarlosimulationsofthickchainlikeclusterscomposedofferromagneticfineparticles.JColloidInterfaceSci,1996,181(2):4224286MasayukiA,AkiraS.Two-dimensionMonteCarlosimulationsofacolloidaldispersioncomposedofpolydisperseferromagneticparticlesinanappliedmagneticfield.JColloidInterfaceSci,2005,288(2):4754887CastroLL,daSilvaMF,BakuzisAF,etal.Aggregateformationonpolydisperseferrofluids:AMonteCarloanalysis.JMagnMagnMater.2005,293:5535588,,,...1995,5(1):1051139YoshihisaE,KatsumiO,MasafumiO.Simulationstudyonmicrostructureformationsinmagneticfluids.PhysicaA,2003,330:49650610AkiraS,CoverdaleGN,ChantrellRW.Stokesiandynamicssimulationsofferromagneticcolloidaldispersionssubjectedtoasinusoidalshearflow.JColloidInterfaceSci,2000,231(2):23824611MohebiM,JamasbiN,LiuJ.Simulationoftheformationofnonequilibriumstructureinmagnetorheologicalfluidssubjecttoanexternalmagneticfield.PhysRevE,1996,54:5407541312CoverdaleGN,ChantrellRW,SatohA,etal.Moleculardynamicmodelofthemagneticpropertiesandmicrostructureofadvancedmetalparticledispersions.JApplPhys,1997,81(8):3818382013RusselWB,SavilleDA,SchowalterWR.ColloidalDispersion.Cambridge:CambridgeUniversityPress,1989