B-2 Stealth Bomber

Embed Size (px)

Text of B-2 Stealth Bomber

ACloserLookattheB2Configuration

TheB2Bomber

DavidCross,JoelFaber,andRaulTelles AOE4124TeamProject April1,2009

BriefHistory TheB2isarevolutionaryaircraft Uniqueflyingwingconfigurationwiththefollowingdesignobjectives Serveasamultirolebomber Stealthwasextremelyimportant Hadtobeabletoflylongmissions

Development Beganinthe1970s FirstoffthelineinNovemberof1988 FirstFlightwasJuly17,1989 In1991,B2designteamwasawardedtheCollierTrophy 1999inKosovo 2001inAfghanistan February22,2008,firstreportedaccidentofB2 HumidityonsensorswereyieldingskewedpreflightchecksJanesMilitaryAircraftRecognitionGuide,2007

B2inAction:

SpecificationsFirstflight: Classification: Span: Length: Grossweight: Cruisingspeed: Range: Ceiling: Power: Accommodation: Armament: RunwayLength: Cost: 17Jul89 Bomber 172feet 69feet 336,500pounds Highsubsonic 6,000milesplus 50,000feet Four19,000poundthustF118GE100engines 2crew Morethan40,000poundnuclearorconventionalweaponpayload 6500feet $2billion

JanesMilitaryAircraftRecognitionGuide,2007

Geometry(0.0,0.0)PlanformArea: MeanAerodynamicChord: XCentroid: SpanwisepositionofMAC: XLeadingEdgeofMAC: QuarterChordofMAC: AspectRatio: AverageChord: TaperRatio: LESweep: 5118.55ft2 39.47ft 40.21ft 29.53ft 20.47ft 30.34ft 5.78 29.76ft 0.00 34.74deg

(48.20,43.84) (56.75,13.00) (59.63,86.00) (69.80,72.60)PictureSource:http://www.aerospaceweb.org/aircraft/bomber/b2/b2_schem_01.gif DataSource:UtilizedWingPlanAnalCodetogeneratedata

(67.28,0)

(63.15,21.34)

CGlocationCGlocationwascalculatedbylooking atthesideprofileoftheB2. Assuminga15anglebetweenthe ReferenceDatum landinggeargroundcontactandthe NP cglocationandassumingthecgwas locatedforwardofthelandinggear, thecgwascalculatedtobearound 33.2feetaftofthereferencedatum line. NeutralPoint:32.98ftaftofnose StaticMargin:0.22ftz

x

PictureSource:http://www.aerospaceweb.org/aircraft/bomber/b2/b2_schem_01.gif DataSource:UtilizedVLMpcCodetogenerateneutralpointdata

CdoatVariousAltitudesNotebyMason,thiswasrunatadifferentaltitude(Re)

M=0.79

DataSource:UtilizedFRICTIONcodefrom http://www.aoe.vt.edu/~mason/Mason_f/ MRsoft.html

SpanloadingComparison

e=0.96 Cl=1

DataSource:UtilizedLIDRAGCodefrom http://www.aoe.vt.edu/~mason/ Mason_f/MRsoft.html

TwistDistributionforMinimizedDrag

DataSource:UtilizedLAMDESCodefrom http://www.aoe.vt.edu/~mason/ Mason_f/MRsoft.html

OptimizedSpanloading

DataSource:Usedspanloadingdata outputfromLAMDESprogramfoundat http://www.aoe.vt.edu/~mason/ Mason_f/MRsoft.html

SectionClforB2

DataSource:UtilizedVLMpcCodeout putforsectionCLsfrom http://www.aoe.vt.edu/~mason/ Mason_f/MRsoft.html

CLatVariousAltitudes

DataobtainedfromLift equationatMach=0.79and thecorrespondingdensities foreachaltitude.

LifttoDragRatio

DataSource:http://www.aoe.vt.edu/~mason/Mason_f/ConfigAeroAppD.pdf

TakeoffandLanding Groundeffect:- Largeareaflyingwing - Sitsoncushion - Hastobeforcedtoland - Notdifficult(2ndeasiesttotheF15)

Stealthdesignledtogreatliftingfeatures.

ControlSurfaces B2has4pairsofcontrolsurfaceson thewingtrailingedge. 1)Splitdragruddersonouterwing 2)Oneelevononouterwing 3)Twoelevonsoninnerwing 4)Beavertail Outerelevonsprovideprimarypitch &rollcontrol. 2innerelevonsconsidered secondarycontrolsurfaces(usedat lowspeed). Beavertailworksconstantlyto alleviategustloads.

Atlowspeedflight,dragrudders areopen.

PictureSource:http://people.clarkson.edu/~pmarzocc/AE430/AE4305.pdf http://people.clarkson.edu/~pmarzocc/AE430/AE4305.pdf StabilityandControlofConventionalandUnconventionalAircraftConfigurations:By BerndChudobaPage201 http://science.howstuffworks.com/stealthbomber2.htm

StealthLowObservableCharacteristics RADARcrosssection(RCS) Infraredsignature Appearance ElectromagneticSignature AcousticSignature

Picturesource: http://www.is.northropgrumman.com/systems/b2spirit_assets/photos/ hi/01top20_94a65408.jpg

Stealth ThekeytoStealthisknowhowRADARwavesarereflectedoff abody. RADARwavesreflectsimilartolightrays. Alightraywillreflectoffasurfacethesameangleatwhichit encounteredthesurface. TogetareturnaRADARreflectionrequiresasurface perpendiculartotheincomingwave.ReferenceData: http://www.aoe.vt.edu/ ~mason/Mason_f/ ConfigAeroStealth.pdf http://www.answers.com/ topic/stealthaircraft http://en.wikipedia.org/ wiki/B2_Spirit

StealthTheB2outerprofilehasavariableradius/ continuouscurvethatdeflectsRADARwaves atanyangle(nontangentialsurface).Thus, reducingitsRCS. Itsshapealsoallowsforaerodynamicflow. TofurtherreduceitsRCStheskiniscoated withRADARAbsorbingMaterials(RAM)ReferenceData: InsidetheStealthBomberByBillSweetman (page2526) http://www.answers.com/topic/stealthaircraft http://en.wikipedia.org/wiki/B2_Spirit PictureSource: http://www.is.northropgrumman.com/systems/b2spirit_assets/ photos/hi/01top20_95020910.jpg

target

Transmitter/receivers

QUESTIONS???

Picturesource:GoogleImagesSearchB2