3配置總體布局設(shè)計

Outline

Whatisaircraftconfiguration

Conventionalconfiguration

Layoutcharacteristics

Variationsofbasicconfiguration

Alternativeconfiguration

Creativityandconfigurationdesign

Specialconsiderations

WhatIsAircraftConfiguration

Definitionofconfiguration

Arrangementofpartsorelements

Definitionofaircraftconfiguration

Arrangementofprimaryaircraftcomponents,suchas

Powerplantorpropulsionsystemlayout

Winglayout

Empennagelayout

Landinggearlayout

Whatisconventionalconfiguration

Acantilevermonoplanewing

Separateverticalandhorizontaltailsurface

Adiscretefuselageusedtoprovidevolumeandcontinuitytotheairframe

Aretractabletricyclelandinggear

LayoutCharacteristicsofConventionalConfiguration

Powerplantlocation

Airintakes

Verticallocationofthewing

Empennage

Landinggear

Noselocation–propellerpropulsion

Foraircraftwithasingletractorpropellerengine

Advantages

Propellerclearance

Self-containedandindependentoftherestoftheaircraft

Disadvantages

Poorvisibility

Fuselagecenter/aftburiedlocation

Forsingleandtwinenginemilitaryjettrainerandcombattypes

Advantages

Compactoveralllayout

Disadvantages

Difficultmaintenanceaccessandengineremoval

A320

C-130

Wing-mountedpowerplants

Formajorityoflargeraircraft

Advantages

Reductionofstructureweight

Compact:fuselageisshorter

AccessforEnginemaintenanceisconvenient

Easycontrolofcenterofgravity

Disadvantage

Oppositeofadvantageofrearfuselagepoddedpowerplants

CitationX

HawkerHorizon

Rearfuselagepoddedpowerplants

Forbusinessjetandmoderatelylargetransport

Advantages

Cleanwing:CLishigher

Easycontrolwhenoneofenginesfails

Landinggearisshorter

Lessnoiseinthecabin

Lowerdrag

Disadvantage

Oppositeofadvantageofwing-mountedpowerplants

Upperorlowerpoddedpowerplant

–Forsomeunmannedaircraft

Tosimplifiedfuselagelayout

Pitot(nose)intake

Advantages

Compact

Disadvantage

Excessivelength

Occupyinganundesirablylargepartofthefuselagevolume

lighting

Sideintakeabovewing

Forlow-wingtrainer/attacker

Advantages

Minimumintakelength/Lowvolumerequirement

Disadvantage

Flowdistortion

Sideintakesbelowwing

Locatedbelowamidtohighwing

Morecommonlayoutthanabove-wingintakes

Advantages

Enhanceflowathighanglesofattackbyextendingthewingleadingedgeaboveintakes

Su-27

FlyingLeopard

Ventralintakes

Advantage

Forhighperformancefighterwherehighangleofattackmanoeuvrabilityisimportant

Disadvantage

Concernabouttheprobabilityofdebrisingestionduringgroundoperation

殲10

F-16

Upperfuselage,dorsalintakes

Fortransportwiththreeenginesorstealthyaircraft

Notrecommended

Operateonlyatlowangleofattack

運(yùn)-8

Highwing(上單翼)

Mid-wing(中單翼)

Lowwing(下單翼)

Thechoiceofwinglocationisacompromisebetween:

aerodynamic

Structure

operationalconsiderations

Aerodynamicconsiderations

Midwing

Lowestinterferencedrag

Advantageousforasupersonicaircraft.

Lowwing

Enabletheflaptobecontinuous

Highwing

Beneficialinhavinganefficientspanwiseliftdistribution

Lowdragduetolift

Structureconsiderations

Thedesirabilityofhavinganuninterruptedwingstructurehasasubstantialimpactontheverticallocationofwing.

Ahighwingorlowwinghasanadvantageoveramidwing.

Operationalissues

Clearance

Highwingisadvantageous

Passengerappeal

Highwingisadvantageous

Crashworthiness

Lowwingisadvantageous

ComparisonsofVerticalLocationoftheWing

Highwing

Mid-wing

Lowwing

Interferencedrag

2

1*

3

Lateralstability

1

2

3

Visibilityfromcabin

1

2

3

Landinggearweight

3**

2

1

Structurelayout

1

3

1

Installingengine

1

2

3

Whylow-wingconfigurationforpassengerjet

Thebeamsofwingcanbecontinuousacrossthefuselageunderthefloor.

Landinggearsareshort.

A320

Easyaccessforenginemaintenance

Crashworthinessconsideration

Whyhigh-wingconfigurationformilitarytransports

Operationrequirement

– Floorofthefuselagemustbeclosetotheground

Highwing

Freightaircraft

Smallerpropeller-poweredtransportaircraft

Somelightaircraft,especiallysingle-enginestypes

Somecombataircraft,includingV/STOLtypes

Unmannedaircraft

Midwing

Somehighperformancecombattypes

Weaponssystemaircraftwithalonginternalweaponsbay

Possiblymulti-decktransportaircraft

Lowwing

Majorityofpassengertransportaircraft

Somelightsingle-andtwin-enginetrainers

Somecombataircraft,includingthosewhichuseofcanardconfiguration

Thebasicconfigurationforthetailsurface

Ahorizontalfixedtailplane(Stabilizer)+

Elevator

Averticalfixedfin+Rudder

Adorsalfairing

Variationsonthebasicarrangment

Variableincidencetailplane

Toadjustthepitchtrimoftheaircraftespeciallywhendeploymentofthehighliftdeviceintroducesignificantpitchingmomentincrements

Allmovingtailplane

Usedastheprimarypitchcontrolwiththeelevator.

Offeringsignificantadvantageattransonicandsupersonicspeed,becauseeffectivenessofconventionaltrailingedgecontrolismuchreduced.

Verticalpositionofhorizontaltail

Thehorizontaltailiswithinthewingdownwashwhichhastheeffectofreducingtheeffectivenessasastabilizer.

Thedegreeofthisreductionisafunctionoftheverticallocationofthetailrelativetothewing

Possiblelocation

“T”tail

Highmounted

Lowmounted

ConsiderationsofVerticalpositionofhorizontaltail

Lessinterferenceofdownwashfromthewing

Easyforstructurelayout

Location

high

middle

low

“T”

Veryhigh

Structureweight

ExamplesofHorizontalTailPosition

米格15

波音717

Threetypeoflayout

Tailwheel

Tricycle

Bicycle

Tricycleisusedmostcommonly

Fixedorretractable?

whenV<150（kts）,fixedlandinggear

whenV>150（kts）,retractable

Loadallocation

Noseleg:6-14%ofmass

Mainleg:~45%ofmass(each)

Lateraldispositionofmainwheels

Mustprecludeanytendencytooverturn

ThelandinggearofBoeing-747andC-5A

Morelegsandwheelsareneededforverylargeairplanes

ExamplesofLandingGear

VariationsofBasicConfiguration

Bracedwing

Advantage:reductioninstructuremass

Disadvantage:dragpenalty

Beusedonsmallaircraftflyingatlowspeed

Canbeusedonlargetransport?

Whysweep

Primaryreason

Todelaytheonsetofcompressibilitydrag

Otherreasons

Tofacilitatelandinggearandstowagebehindtheprimarywingstructure

Toenhancestaticlongitudinalstability

F-86

轟六

Whyforwardssweep?

Advantage:beneficialinachievinghighermaximumlift

Disadvantage:pronetoaeroelasticdivergence

VFWHansaJet

Sweepangle

Theamountofsweepshouldbetheminimumrequiredforaerodynamicreasons.

Largesweepanglearerequiredtomaintainsubsonicleadingedgeflowwhenanaircraftisflyingsupersonically.

Alowspandetlawingbecomesadvantageous.

Winglet(WingTipFins)

Toreducedragduringcruisebyeffectivelyincreasingthewingspan

A330

Twinbooms

Whatistwinboomsconfiguration

Twinboomsextendingaft

Whyistwinboomsconfigurationused?

Provisionforpusherpropellerforageneralaviationorunmannedaircraftwhereenginemassissuchthatitmustbelocatedclosetothecenterofgravityoftheaircraft.

Togiveunrestrictedaccessforarearfreighthold

Tailwheellayout(后三點)

Advantage

Simpleandlight

Disadvantages

Groundmanoeuvringismoredifficult

Poorvisibility

Take-offandlandingismorecomplex

Suggestion

Limitedtolightaircraftwhereoperationalpenaltiesareacceptedinexchangeforsimplicity.

Bicyclelayout(自行車式)

Advantage

Anunclutteredwingandalongfuselagefreefromlandinggearcomponents

Disadvantages

Thehighlyloadednoseleg

groundmanoeuvringandrotationattake-offdifficult

Needforaspeciallandingtechniquestoavoidextremenoselegloadsduringtouchdownandbraking

Suggestion

Shouldnotbeusedunlessthereisnoacceptableoption

AlternativeConfigurations

Alternativeconfigurationshouldbeconsideredonly:

Ifaclearadvantageisidentified

Ifthecorrespondingdisadvantageispresented

Typicalunconventionalconfigurations

Biplane

Butterflytail

Taillesslayout/Flyingwing

Variablesweep

Canardlayout

Threesurfaceconfiguration

JointedWingConfigurations

DoubleFuselageConfigurations

Biplane

Usedintheearliestdayofaeronautics

Largewingareawasrequired

Dragpenaltybecameunacceptablewhenspeedincreased

NowadayscanbeusedinaerobaticaircraftandMAV

Lowwingloading

ButterflyTail

Thehorizontalandverticaltailsurfacearecombinedintoapairofinclinedsurface.

Advantage

Smallertotalsurfaceareaandlessinterferencedrag

Disadvantage

Cross-couplingofstabilityandcontrolcharacteristics

Advantage

Lowobservability

Lowdrag

Disadvantage

Longitudinalcontrolislimited.

Theneedtokeepthecenterofgravitymovementwithinasmallrange.

Becauseoflateralstabilityandcontrolproblem,averticalfinisoftenneeded.

Arudimentaryfuselageisoftenrequiredforpayloadvolume.

VariableSweep

Highlysweptwingscanpossespoorlowspeedaerodynamiccharacteristics

Variablesweepconfigurationstrytoovercomethisproblembymatchingthesweepangletotheidealatgivenflightspeed

Advantage

Canardtrimforcesaregenerallyinthesamedirectionasthoseonthewing

Trimmedmaximumliftcoefficientishigher

Bettertrimmedlift-to-dragratios

Designconsideration

Airflowfromthecanardinterfereswithwing,anditisessentialtomatchthelayoutgeometrytoachievethebestoverallresult.

Thecanardmuststallbeforethewingwithflapsupaswellasdown,otherwiseuncontrollablepitch-upcanoccur.

Threevariations

Longcoupled

Asmallcanardislocatedsufficientlyforaheadofthewingthattheinterferenceeffectsaresmall.

Beneficialbothintermsofcruisetrimdragandatlowspeed,especiallytake-offrotation

Shortcoupledwithdeltawing

Acanardisplacedjustaheadofthewing

Carefullocationofthetwocomponentsenablesthelifteffectivenessofthepairtoexceedthatofsumoftheirisolatedvalues

Canardwithforwardsweptwing

ExamplesofCanardLayout

AD-100andAD-200

DesignforStallPrevention

WhycanardforLongEZ

Amateursflyit!

Itisessentialtopreventtheairplanetobestalled

WhycanardforProteus

UniqueConfigurationAdaptstomanyMissionRequirements

Threesurfaceconfiguration

JointedWingConfigurations

Lowerstructureweightbecauseofimprovedstiffnessintorsionandbending

Built-indirectliftanddirectside-forcecapability

Reducedinduceddrag

Reducedtransonicandsupersonicwavedragaswellasimprovedarearuling

DoubleFuselageConfigurations

WingInGround

ConsiderationsofConfigurationDesign

Generalcomments

Nologicalproceduretoproduceanuniqueconfiguration

Canberadicallydifferentconfigurationswithsimilarmissionperformance

Anexampleofradicallydifferentconfigurationswithsimilarmissionperformance

Vulcan

B-47

Wto

81.6T

79T

payload

9.5T

10T

Vmax

1038km/h

1050km/h

range

7650km

6500km

AVROVulcan:

tailless

deltawing

4engines

BoeingB-47:

conventional

sweepwing

6engines

ConsiderationsofConfigurationDesign

Considerations

Technicalaspects

Marketingaspects

Emotionalandstylingconsiderations

Itisnearlyalwaysdesirabletoplacethefuelc.g.,thepayloadc.g.,andemptyweightc.g.,atsamelongitudinallocation.

Thisconsiderationhasamajorinfluenceontherelativeplacementofthoseairplanecomponents,whichprimarilyaffecttheoverallc.g.location.

ThecriticalMachnumberofthewingofasubsonicairplaneshouldbeselectedsuchthattheairplanedoesnotcruisetoofarintothedragrise.

–Thisrequirementmeansthatwingsweepangle,airfoiltypeandairfoilthicknessratiomustbechoseninsuchawaytoavoidexcessivedragriseatcruiseMachnumbers.

ThecriticalMachnumberofthewingshouldalwaysbelowerthanthecriticalMachnumberofstabilizingorcontrolsurfaces.

Thisrequirementmeansthatthethicknessratio,sweepangleandaspectratioofstabilizingorcontrolsurfacesmustbeselectedtoyieldcriticalMachnumbergreaterthanthatofthewing.

Theintegrationofmajorcomponentssuchasnacelleonthewing,wingonfuselageandsoonneedstobedonesothatinterferencedragisminimized.

Ideallythismeansthatanyconnecting,intersectingitemsshouldintersectatascloseaspossibleto90degrees.

Ifitisnotpossibletodothis,extensivefairingsareneededtoavoidinterferencedragpenalties.

Majorintersectingstructurecomponentsshouldbearrangedtoavoidduplicationofspecialheavystructure.

Think“structuresynergism”

Lowweightairplanestructurescomeaboutonlybyjudiciouslycombiningmultiplefunctionsintomajorstructureelements.

Forexample:

Inhighwingtransportwithfuselagemountedmainlandinggear,itisdesirabletoattachthelandinggeartothesamefuselageframewhichareusedtoattachthewing.

Indecidingonthelocation