Aerial Metamorphosismason/Mason_f/variablesweepS03.pdf · 2011. 4. 1. · Variable Sweep Wings AOE 4124 3 The Jet Age Advances in propulsion in 1930’s made sustained high-subsonic,

AOE 4124AOE 4124

Aerial Metamorphosis:Aerial Metamorphosis:Variable Sweep WingsVariable Sweep Wings

Brian HayesBrian Hayes

Eugene HeimEugene Heim

1

Variable Sweep WingsVariable Sweep Wings 22AOE 4124AOE 4124

OutlineOutline

The Jet AgeThe Jet Age

Aerodynamic Lift At Supersonic SpeedAerodynamic Lift At Supersonic Speed

Increasing Critical Mach NumberIncreasing Critical Mach Number

In-Flight OptimizationIn-Flight Optimization

Pivoting Around StallPivoting Around Stall

Variable Sweep Variable Sweep –– Variable Mission Variable Mission

Variable Sweep AircraftVariable Sweep Aircraft


The Jet AgeThe Jet Age

Advances in propulsion inAdvances in propulsion in

19301930’’s made sustained high-s made sustained high-

subsonic, transonic, andsubsonic, transonic, and

supersonic flight possiblesupersonic flight possible

High-speed WWII era aircraftHigh-speed WWII era aircraft

typically had strait wings andtypically had strait wings and

thickness ratios of 14 to 18thickness ratios of 14 to 18

percentpercent

3

http://www.acepilots.com/planes/p51_mustang.html

http://www.acepilots.com/planes/p38_lightning.html


Aerodynamic Lift At Supersonic SpeedAerodynamic Lift At Supersonic Speed

19351935 Adolf BusemannAdolf Busemann, Aviation, Aviation

Research Organization, GermanyResearch Organization, Germany

1941 Michael 1941 Michael GluhareffGluhareff,, SikorskySikorsky

chief of designchief of design

1945 Robert T. Jones, NACA1945 Robert T. Jones, NACA

Langley aerodynamicistLangley aerodynamicist

http://www.hiller.org/about-us/briefings-journal/briefings/2000q4.pdf

2


Independence of velocity components is true only forIndependence of velocity components is true only forinvisid flowinvisid flow

OverestimatesOverestimates M Mcrcr,,LL

Increasing Critical Mach NumberIncreasing Critical Mach Numberhttp://www.eng.vt.edu/fluids/msc/gallery/shocks/p25b.htm

1


Thickness Ratio and Sweep AngleThickness Ratio and Sweep Angle

1


Problems At StallProblems At Stall

Serious S&C problems at high Serious S&C problems at high aa near stall near stall

NACA Bell L-39 swept wing flight studyNACA Bell L-39 swept wing flight study

1


Effect On Span LoadingEffect On Span Loading

1


Stall Stability BoundaryStall Stability Boundary

1


In-Flight OptimizationIn-Flight Optimization

1


Pivoting Around StabilityPivoting Around Stability

1


Variable SweepVariable Sweep –– Variable Mission Variable Mission

4


Variable Sweep AircraftVariable Sweep Aircraft

1


Bell X-5Bell X-5

Sweep varied from 20Sweep varied from 20°°to 60to 60°°

Mach 0.81 showedMach 0.81 showeddramatic performancedramatic performancedifferences for varieddifferences for variedsweepsweep

Short field landingShort field landingand take offand take off

High rate of climbHigh rate of climb

Good loiter capabilityGood loiter capabilityhttp://users.dbscorp.net/jmustain/x5.htm


Grumman XF10F-1Grumman XF10F-1

Sweep varied fromSweep varied from

13.513.5°° to 42.5 to 42.5°°

Goals:Goals:

Reduce transonicReduce transonic

dragdrag

Low speed takeoff /Low speed takeoff /

landing for carrier uselanding for carrier use

http://jpcolliat.free.fr/xf10/xf10.php3


XF10F-1 VS F3H-1XF10F-1 VS F3H-1

Variable sweepVariable sweep

provided:provided:

Reduced landingReduced landing

speedspeed

Higher max speedHigher max speed

Increased RangeIncreased Range

XF10F-1 F3H-1

Weight 27,351 25,650 lbs

Wing area 467 - 450 442 ft^2

Span 36.8 - 50.6 35.3 ft

Stall speed 78 96 knots

Max speed 617 592 knots

Range 1450 1025 miles

XF10F-1 F3H-1

“Variable Sweep Wing Design”


General Dynamics F-111General Dynamics F-111

Navy: carrier basedNavy: carrier based

Air force: long rangeAir force: long range

Combination ofCombination of

requirements led torequirements led to

variable sweep designvariable sweep design

Sweep varied from 16Sweep varied from 16°°

to 72.5to 72.5°°

http://www.globalsecurity.org/military

/systems/aircraft/f-111-pics.htm


Grumman F-14Grumman F-14

Carrier based airCarrier based air

defensedefense

Low speed take off /Low speed take off /

landinglanding

Capable of Mach 2.4Capable of Mach 2.4


to 68to 68°°

http://www.anft.net/f-14/f14-detail-wsm-04.htm


F-14 Sweep MechanismF-14 Sweep Mechanism

Disadvantages:Disadvantages:

Added complexityAdded complexity

Added weightAdded weight

Really add weight?Really add weight?

Larger wing areaLarger wing area

Larger enginesLarger engines

http://www.anft.net/f-14/f14-detail-wsm-04.htm


F-14 Sweep BenefitsF-14 Sweep Benefits

Combines low andCombines low and

high speedhigh speed

performanceperformance

Airfoil for subsonicAirfoil for subsonic

and supersonicand supersonic

Reduced drag toReduced drag to

weight ratioweight ratio

Lower thrust toLower thrust to

weight requiredweight required

“Variable Sweep Wing Design”


Rockwell International B-1Rockwell International B-1


to 67.5to 67.5°°

Forward swept:Forward swept:

Takeoff / landingTakeoff / landing

High altitude cruiseHigh altitude cruise

Aft swept:Aft swept:

High subsonic flightHigh subsonic flight

Supersonic flightSupersonic flighthttp://www.globalsecurity.org/wmd/systems/b-1.htm


SwitchbladeSwitchblade

Possible design ofPossible design of

forward variableforward variable

sweepsweep

Leading edgeLeading edge

becomes trailing edgebecomes trailing edge

Thought to be theThought to be the

now unveiled Boeingnow unveiled Boeing

bird of praybird of pray

http://www.area51zone.com/aircraft/switchblade.shtml


ReferencesReferences

1.1. http://www.http://www.hqhq..nasanasa..govgov/office//office/paopao/History/SP-468/cover./History/SP-468/cover.htmhtm

2.2. http://www.http://www.hqhq..nasanasa..govgov/office//office/paopao/History/SP-4406/cover.html/History/SP-4406/cover.html

3.3. http://inventors.about.com/library/inventors/bljetengine.http://inventors.about.com/library/inventors/bljetengine.htmhtm

4.4. http://www.hq.nasa.gov/office/pao/History/SP-440/http://www.hq.nasa.gov/office/pao/History/SP-440/ covercover..htmhtm

5.5. http://users.dbscorp.net/jmustain/x5.htmhttp://users.dbscorp.net/jmustain/x5.htm

6.6. http://www.vectorsite.net/avb1.htmlhttp://www.vectorsite.net/avb1.html

7.7. http://www.area51zone.com/aircraft/switchblade.shtmlhttp://www.area51zone.com/aircraft/switchblade.shtml

8.8. http://www.globalsecurity.org/military/systems/aircraft/f-111-design.htmhttp://www.globalsecurity.org/military/systems/aircraft/f-111-design.htm

9.9. http://www.anft.net/f-14/index.htmhttp://www.anft.net/f-14/index.htm

10.10. http://www.globalsecurity.org/military/systems/aircraft/f-14.htmhttp://www.globalsecurity.org/military/systems/aircraft/f-14.htm

11.11. ““Variable Sweep Wing DesignVariable Sweep Wing Design”” by: Robert W. Kress by: Robert W. Kress

12.12. Bullets and lower right figure courtesy ofBullets and lower right figure courtesy ofhttp://www.bestanimations.com/Military/Planes/F-14/F-14.htmlhttp://www.bestanimations.com/Military/Planes/F-14/F-14.html

13.13. Virginia Tech logo courtesy of Virginia Tech logo courtesy of http://filebox.vt.edu/vaes/HRAREC/images/http://filebox.vt.edu/vaes/HRAREC/images/


Questions?Questions?

http://www.3dmodelworks.com/redir.asp?Page=thumb-show.asp%3FMODEL%3D706


Cool PictureCool Picture


Free Flight F-111Free Flight F-111

Aerial Metamorphosismason/Mason_f/variablesweepS03.pdf · 2011. 4. 1. · Variable Sweep Wings AOE 4124 3 The Jet Age Advances in propulsion in 1930’s made sustained high-subsonic,

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