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1、J.theor.Biol.(1999)199,291}295ArticleNo.jtbi.1999.0959,availableonlineathttp://www.idealibrary.comonHeatTransferthroughPenguinFeathersCOLINDAWSON*-,JULIANF.V.VINCENT*,GEORGEJERONIMIDIS*,GRAHAMRICE?ANDPAULAFORSHAWA*CentreforBiomimetics,;niversityofReading,ReadingRG66A¹,;.K.;?DepartmentofEnginee
2、ring,;niversityofReading,ReadingRG62A>,;.K.andADefenceClothingand¹extileAgency,Flagsta+Road,Colchester,EssexCO27SS,;.K.(Receivedon9October1998,Acceptedinrevisedformon20April1999)Morphologicalmeasurementsofpenguinfeathersareusedtoconstructathermalmodelofheattransferthroughthecoat.Assumingunifor
3、mdistributionofthefeathersandtheirassociatedafterfeathers,itispossibletomodelheattransferthroughthecoatofthepenguinusingstandardtheory.Itisshownthatconvectiondoesnotoccurinthecoatofthepenguinandthatradiativeheatlossisminimized.Thetheorypredictsathermalconductivityof2.38Wm~2K~1whichcompareswell
4、withanempiricallymeasuredvalueof1.93Wm~2K~1.(1999AcademicPressIntroductionbody(30}40percm2)ratherthanarrangedintracts.Penguinsareaspecializedgroupofnon-#ying,Forinsulationthepenguinrequiresathick,aquaticbirdsthatliveinthesouthernhemi-air-"lled,windproofcoat(similartoanopen-cellsphere,mostfamou
5、slyintheAntarctic.Theabil-foamcoveredwithawindprooflayer)thatelim-ityofsomespeciestowithstandextremecoldinatesconvectionandreducesradiativeandcon-whilstfastingforupto120days(duringeggvectiveheatlossestoaminimum.incubation)hasexcitedmuchattention.SeveralHowever,whendiving,thepenguinrequiresstud
6、ieshaveinvestigatedthethermalresistanceathin,smoothandwaterproofcoatwithnotrap-ofpenguin&&coats''(featherandskinassembly)pedair(positivebuoyancywouldbeabigdisad-andfoundittobesurprisinglylow*anaveragevantagetoanactiveswimminghunter*Wilsonof0.74m2KW~1or7.4Tog(Drent&Stone-etal.,1992).Itachievest
7、hisbyusingmuscleshouse,1971;Jarman,1973;Pinshowetal.,1974;attachedtotheshaftofthefeatherto&&lockKooymanetal.,1976).down''thefeatherstocreateawater-tightbarrierPenguinfeathersareheavilymodi"ed,being(Kooymanetal.,1976).Inaddition,thefeath