Expanding the range of possibilities-Biomimetics

Airplane Design: Past, Present and Future – An Early 21st Century Perspective

John H. McMastersTechnical Fellow

The Boeing Companyjohn.h.mcmasters@boeing.com

and

Affiliate Professor

Department of Aeronautics and Astronautics

University of Washington

Seattle, WA

April 2007

Ed Wells Partnership Short Course

Based on: American Institute of Aeronautics and Astronautics (AIAA) & Sigma Xi Distinguished Lectures &

Von Kármán Institute for Fluid Dynamics Lecture Series: “Innovative Configurations for Future Civil Transports”, Brussels, Belgium June 6-10, 2005

Notation and Symbols Used

A Area (ft.2, m2)a Speed of sound (ft./sec., m/s)AR Aspect ratio, b/č = b2/Sb Wing span (ft., m)č Average wing chord (ft.,m)CF Force coefficients (lift, drag, etc.) = F/qSCℓ Section (2D) lift coefficientCM Moment coefficient = M/qSĉCp Pressure coefficient = Δp/qD Drag force (lb., N)E Energy (Ft.-lbs., N-m)e “Oswald efficency factor”ew Wing span efficiency factor (= 1/kw )F Force (lift, drag, etc.) (lbs., N)H Total head (reservoir pressure)I Moment of inertiakw Wing span efficiency factor (= 1/ew)L Lift force (lb., N)ℓ Length (ft., m)M Mach number (V/a)M Mass (kg)M Moment (ft. lbs., N m)P Power (ft.-lbs./sec., N-m/sec.)p Static pressure (lbs./ft.2)

q Dynamic pressure (lbs./ft.2) = ½ρV2

R Range (mi., km)Rn Reynolds number (ρVℓ / μ)S Wing area (ft.2, m2)T Thrust (lb., N)T Temperature (oF)u Local x-direction velocity componentV Velocity, Speed (ft./sec., m/s, mph, km/h)v Local y-direction velocity componentw Downwash velocity (ft./sec., m/s)ż Sink rate (vertical velocity) (ft./sec., m/s)

Greek:α Angle of attack (deg.)Γ Circulationγ Climb or glide angle (deg., rad.)γ Ratio of specific heats in a fluidε Wing twist angle (deg.)θ Downwash angle (deg.)φ Velocity potentialΛ Wing sweep angle (deg.)μ Dynamic viscosityν Kinematic viscosity (μ/ρ)ρ Fluid mass density (kg/m3)

• Expanding the range of possibilities (Biomechanics of flight and morphing aircraft)

Presentation Overview

A Cosmic View of Aviation History

BigBang

Solar SystemFormed

LifeEvolves On Earth

Dinosaurs Birds

Man Wright Bros. Boeing

Neilgoes tothe Moon

Insects

Future ofEarth ?

Future ofThe World Economy ?

Mass extinctionfrom space

Global climate change

X

??

~ 300 million years of flight

To address societal needs and sustain an industry that continues to contribute to our national and global economy:

– Build an effective, efficient, safe

and environmentally acceptable

global air transportation system

– Contribute to our national security

in the face of an increasing number

of non-traditional threats

– Provide an important component

to the “affordable access to space”

21st Century Challenges for Aeronautics

A Developing World-Wide “Perfect Storm” ?(Some Global Challenges for the 21st Century)

Increasing World Population

Engineers play a fundamental role in any solutions or ameliorations!

“I’m sure glad the hole isn’t in

our end…”

GlobalClimate Change

Cultures/InstitutionsUnable or Unwilling

To Change

Finite Supply of Key Natural Resources

(Oil, Water, Minerals)

We, as a global community,are all in this together.

The Nine Dot ProblemThe Origin of “Out of the Box” Thinking(or a Paradigm for Paradigm Shifting)

Problem: What is the MINIMUM number of straight lines required to connect the nine dots shown without lifting the pencil from the paper?

Solving the Nine Dot Problem

Basic Solution: 5 lines [Government required solution: 6 lines (5 lines to solve the problem and one more to assure compliance)]

Solving the Nine Dot Problem (2)

The Creative Rocket Scientist’s Solution: 4 lines

Solving the Nine Dot Problem – The Final Frontier

An 8-year Old Student’s Solution: Transform the nine dot problem into a “one dot” problem and jam a pencil through it (i.e. one line)

Fold

Fold

Thanks to Dr. Paul B. MacCready Jr.

Yes, it this is an “exact solution”; one line 9 thickness’ of paper in length.

Opportunities in the Knowledge DomainA balanced approach is needed.

Unaware

Aware

KnownUnknown

“What we know we know.”“What we know we don’t know.”

“What we don’t know we don’t know.”

“What someone knows, but that we haven’t found yet.”

KnowledgeRe-use

TargetedResearch

“Prospecting”Hunting & SearchingTraps & Surprises

[Competitive Risk]

Curiosity-based Research

Potentialbig $$$$savings

DARPA land

Paleozoic Era Mesozoic Era Cenozoic Era

345 248 65Million Years Ago

A More Complete View of Aviation History

Insects

Birds

Proto-reptile

Pterosaurs

Anemophilous Seeds

Mammals

Bats

Extinct

Solar Powered Flight

Formation Flight

Micro Air Vehicles (µAVs) Ultra-Quiet Flight

Unsteady Aerodynamics

Extremes in Variable Geometry Wings

Opportunities for Expanding the Range of Aeronautical Inquiry

Joel Grasmeyer’s “Microbat 3”Micro Air Vehicle Attacked by a Seagull

A penny for size comparison

Insects and Entomological Engineering

See Michael Dickinson’s work at Cal Tech at: http://www.dickinson.caltech.edu

McMasters, J. H., “ The Flight of the Bumblebee and Related Myths of Entomological Engineering”, Amer. Scientist, Vol. 77, March- April, 1989, pp. 164-69.

SeattleMuckraker

Aerodynamicist ProvesBumblebees Can’t Fly!

$1..00September 10

Guru remainsin trance

for 20 years..without food or drink

Elvis is Alive,Living in Argentina

Giant flydevours

jumbo jet…. Hundreds missing

News Flash….Britney Spears

to run for governorof New York

A 380

The tabloids do it to scienceagain?

Astrophysicists find dark matter…its cosmic cow poop

The Myth of the Bumblebee – The Aerodynamicist’s Bane

The Actual Origin of the Bumblebee Myth

From A. Magnan, Le Vol Des Insects, Paris: Herman and Cle, 1934 (p. 8):

“Tout d’abord, pouss’e par ce qui fait en aviation, j’ai applique’ aux insectes les lois de la resistance del’air, et je suis arrive’ avec M. [Andre] SAINTE-LAGUE a cette conclusion que leur vol est impossible.”

The Myth of the Bumblebee – The Aerodynamicist’s Bane

Typical Variation in Aerodynamic Efficiency (Lift-to-Drag Ratio) with Reynolds Number

20

10

0

MaximumSubsonic

Lift-to-Drag Ratio

103 104 105 106 107 108

Reynolds Number (based on average wing chord)

“Smooth” Model(Variable Boundary Layer

Transition Locations)

“Rough” Model(Fully Turbulent Boundary Layer)

InsectsBirds

Large Airplane Flight

Sailplanes

Large-Scale Laminar Flow Separation on “Smooth” Models

“Insect-like”Wings

Wind Tunnel Testing

Std. Aero. E. textbooks

Bumblebee

10-5

Bacteriaflagella

Size Matters !

Drag Variation With Reynolds Number

Dra

g c

oe

ffic

ien

t (C

D)

– b

as

ed

on

fro

nta

l a

rea

Reynolds Number (Rn)

Curve for a circular cylinder

Flat plate CD = 2.0(height = d)

Cylinder CD = 1.2(diameter = d)

Streamlined Body CD = 0.12(thickness = d)

Cylinder CD = 1.2(diameter = 0.1d)

Cylinder CD = 0.6(diameter = d)

Rn = 105

Rn = 105

Rn = 105

Rn = 104

Rn = 107

Rn = 15,000

With dimpling

While laminar flow produce lower drag, a turbulent flow is much more resistant to separation.

Aerodynamic Performance of a Crane Fly Airfoil

Tipula oleracea

a b c d e

a b c d e

a-a

b-b

c-c

d-d

e-e

Section Lift

Angle of Attack Section Drag

Section Lift

Tests in glycerin @ Rn = 900

Airfoil A

Airfoil B Airfoil B

A

B

Rees, C.J.C., “Aerodynamic properties of an insect wing section and smooth airfoil compared”, Nature, Vol. 258, 1975, pp.141-42.

Dragonfly Flight Testing and Flow Visualization

http://jeb.biologists.org/cgi/content/full/207/24/4299

Flow Visualization on a Model Insect Wing Oscillating in Pitch

http://jeb.biologists.org/cgi/content/full/207/24/4299

Witold Kasper and Trapped Vortices(“Enhanced Circulation” Wings)

SAAB wing with span-wise jetAngle of Attack - α

Kasper “Bekas” sailplane

Lift - L

Vortex Flaps retracted

Vortex Flaps extended

The Kasper wing does produce the vortices shown, but they have been proven to be unstable unless some method is employed to keep them intact (e.g. the SAAB scheme above). As flown, this was an extremely dangerous airplane. [Kruppa, E.W., “A wind tunnel investigation of the Kasper vortex concept”, AIAA 1977-310, Wash. DC, Jan 10-13, 1977.]

Wakes From Flapping Wings

De Laurier Ornithopter (2006)

Wake behind a cruising butterfly

(Kokshaysky, N.V. “Tracing the wake of a flying bird”, Nature, Vol. 279, 1979, pp. 146-8.)

Various Ways to Create Wings From the Same Basic Set of Bones in Vertebrates

Pterosaur

Bird

BatHuman

Very limited span and area change capability, but as living tissue, the membrane is part of a sophisticated “smart wing” system

Great ability to change span, area, sweep, twist and dihedral – symmetrically and asymmetrically.

Limited ability to change span and area, but powerful ability to control camber and twist.

4

1 2 3

The Wonders of Bird Flight

Thanks to Sharon Finn

Important Aeronautical Technology IncorporatedIn Birds

• Mission Adaptive Wing• Active Controls/ Control Configured Vehicles• Composite structures• Damage Tolerant Structures• Fully integrated System Design• Advanced Manufacturing Techniques

A California Condor (Gymnogyps californianus) in a Glide

The Evolution of Birds

One Possibility for the Origins of Bird FlightA plausible (and probably testable) explanation for a cursorial origin for the evolution of flight in birds due to Phillip Burgers and Luis Chiappe.

Ref. Burgers, P. and Chiappe, L.M., “The wing of Archaeopteryx as a primary thrust generator”, Nature, Vol. 399, 6 May 1999, pp. 60-2.

Tandem Wing Fliers

Rutan “Proteus” (circa the present)

www.scaled.com

Microraptor gui

Northern China125 Mya

77 cm (~ 30 in.)

Ref. Xu, et al., Nature, Vol.421, 23 January 2003, pp. 335-40.V

A feathered analog to a flying squirrel?

The Possible Origin of Birds Within theTheropod Dinosaurs (after Prum, 2003)

Evolution of fourfeathered wings

and gliding

Evolution ofpowered flight,

and loss of hind wings

Microraptor gui(~ 125 mya)

Archaeopteryx lithographica (~ 140 mya)

Richard O. Prum, Nature, Vol.421, 23 Jan. 2003, pp. 323-4

Feathers ?

I personally doubt this (except for the case of insect evolution).

Case Study: The Quiet Flight of Owls Wonders of Owl Wings and Feathers

Owls are:

• Highly evolved and specially adapted primarily as nocturnal predators, often flying in confined spaces

Need to fly slowly and with a high degree of maneuverability• Splendid examples of natural “stealth” technology Approach not detectable by prey while using

highly developed bi-aural direction finding and night

vision

Note: The owl’s adaptations to do these two things are often confused with each other. They turn out to be synergistic.

With thanks to Geoffrey M. Lilley and James Snyder

Lift (L) ~ V2

Drag (D) ~ V2

Weight (W)

Speed (V)

Distance - r

Noise varies as ~ V5 / r2

Aerodynamic forces vary as ~ V2

Basic Physics of Owl – Prey Interaction

Prey

Owl Wings and Feathers Have Special (and Sometimes Unique) Adaptations

• To fly slowly (and thus with low noise) and maneuverable– A wing of relatively large area for its body weight– Special comb-like structures on the leading edges of the

leading primaries that generate vortices that increase lift

• To reduce noise audible to their prey (and not interfere with their own hearing - ”direction finding”)– Feathers with a velvety surface texture reduce mechanical

rubbing and rattle, and “kill” higher frequency air flow noise

– A soft and serrated wing trailing edge that diffuses and damps higher frequency components of air flow noise

Combs on Leading Primaries

Specialized form of vortexgenerators for increasedlift for slow flight andenhanced maneuverability

Velvety featherSurfaces

Reduces both mechanical and aerodynamic noise

Soft, Serrated WingTrailing Edge

Diffuses and reduceshigher frequency edge noise

Owl Feather Adaptations

Leading Edge Combs on the Primary Feathers of an Owl

Owl Wings and Feathers Have Special (and Sometimes Unique) Adaptations

The “Silent” Flight of Owls:

SoundIntensitySPL- sound pressurelevel

Sound Frequency kHz2

Typical spectrumof sound generated by most birds [qualitative only]

Owl noisespectrum

Owl hearing range100Hz - 20 kHz

Lower limit ofprey hearing

range

Owl bi-auralhearing range3 - 6 kHz

10

Mouse squeaks and leaf rattles

Some Conclusions About Owls

• Owls don’t really fly “noiselessly”, they merely manage the noise they generate in relation to the hearing ability of their prey

• Owls are highly and very cleverly adapted for what they do (and where and when they do it)

• Several features of owl feathers are unique among birds (leading edge combs, velvety feathers, soft wing trailing edges)

• Not all owls have all these adaptations (e.g. fishing owls lack leading edge combs)

• Experiments in which the leading edge wing combs and trailing edge fringe were clipped from the wing showed a large deterioration in an owls ability to fly - and noise generated more like that of other birds.

Pterosaurs (with “smart” wings) 150 Million Year of Success

Pterosaurs – 150 Million Year of Success(A Natural Model of Cylindrically Cambered Rogallo Wings)

Rhamphorhychoidae

Pterodactyloidea

Rhamphorhynchus sp.

Pteranodon ingens(Wing span ~ 7 m)

Older “stability configured” sub-order.

Newer “controlconfigured” sub-order (no tails).

Note: Although they share a common ancestor, pterosaurs are not dinosaurs. They existed contemporaneously and also became extinct at the end of the Cretaceous, 65 million years ago.

Rogallo Wings & Hang Gliders

“Batso” circa 1971

The Relative Aerodynamic Efficiency of Conically and Cylindrically Cambered Rogallo

Wings

Lift-to-DragRatioL/D

Lift coefficient - CL

“High” AR cylindrically cambered

How Pterosaurs Really Worked Remains Controversial

Pteranodon ingens

Traditional “Broad Wing” Model

More recent“Narrow Wing”

Conjecture

After R. McN. Alexander

After Bramwell and Whitfield38

After Padian, circa 1985

Awkward quadruped ? Bipedal runner ?

Adult wing span ~ 7 m

The Texas Pterosaur ( Quetzalcoatlus northropi )

California Condor

Max. adult wing span ~ 12 m (~ 39 ft.)

Possible “broad wing”membrane ?

Possible “narrow wing” membrane ?

Conjectural uropatigium

Gravity According to Newton(The Shrinking Earth Hypothesis)

For which there is currently no shred of evidence - yet.

FnFt

Rt Rn

M

m

m

F = k M m R2

Thus: If, say 100 my bp, Rt was 20% larger than now (Rt = 1.2 Rn), and M and m are constant over time, the same object (m) on or near the surface of the Earth would have weighed 31% less then than it does now (Ft = 0.69 Fn).

Where:F = mutual force of attraction (or weight of object of mass m)M = mass of the earthR = distance between the centers of the two massesK = universal gravitational constant

Assume theEarth has been shrinking as it cools since it first formed…..

This example represents an average, almost undetectable change in diameter of less than three meters per century !

The MacCready Robotic Replica of the Texas Pterosaur Quetzalcoatlus northropi (circa 1986)

From the TexasCretaceous circa 70M years ago.

Adult wingspan up to ~ 40 ft.

Pterosaur Brains

Rhamphorhynchus

Rhamphorhynchus

Anhanguera

Non-avian reptiles

Birds

Anhanguera piscator

Pterodactyloids

0 1 2 3 4 5 6 7

Lo

g B

rain

Ma

s s

(mg

)

log Body Mass (g)

5

4

3

2

1

0

Pterosaur Brains

Note: The floccular lobe in pterosaur brains has been found via CAT scans of fossil skulls to be greatly enlarged relative to that in other animals. The purpose of the flocculus is to collect and organize sensory data received from the network of nerves distributed through the animal’s body (including the living tissue in the wing membrane).

Size MattersThe Square-Cube Law Applied to “Geometrically Similar” Animals

L = characteristic length L2 ~ area (surfaces and cross sections) L3 ~ volume (and thus weights)

How big ?

How small ?

L

A B C

Z Y X

Consider a spherical cow:

Mass - Wing Area Relations for Flying Devicesin Comparison with the Square-Cube Law

M = 15 S3/2

M = S3/2

Wing Area

S (m2)

Mass – M (kg)

10 –6 1 106

103

10 -3

1

10 -3

Comparison of Large Soaring Birds

Wandering Albatross(Diomedae exulans)

California Condor(Gymnogyps californianus)

Albatross Condor

Wing Span (m) 3.5 3.0Wing Area (m2) 0.72 1.5Aspect Ratio 17 6Mass (kg) 9.8 10Wing Loading (kg/m2) 13.6 6.6

Different Soaring Modes and Environments Different Geometries

Forces on an Airplane in Steady [constant speed] Glide

Angle of attack (α)

Weight (W)

Lift (L) ~varies with airplane angle of attackDrag (D)

Flight Velocity (V)

In steady flight: Lift (L) = Weight (W) x cos γDrag (D) = W sin γ

For L/D > ~6: Glide angle (γ in rad. ) ≈ [L/D]-1 = ż / V

By standard convention, the component of the total aerodynamic force on the airplane perpendicular to the flight path is the Lift (L) and that parallel to the flight path is Drag (D).

Flight path axis

Airplane geometricReference axisGlide angle (γ)

γ

“Thrust” = Drag = W sin γ

VerticalVelocity(sink rate) ż

The Motions of Real Atmospheres

If the air if moving up faster than a “glider” is “sinking” (descending in still air), soaring becomes possible.

Heating by sun Winds over terrain Thunderstorms

Mountains

LandWater

Upd

raft

s

Do

wn

drafts

To be avoided by small airplanes

Dolphin-Style Soaring Along a Ridge

Selected Glide Polar Comparisons

Sink rate = ż ≈ V/(L/D)Power required for level flight = weight (W) x sink rate = ż W

Wing and Skull Comparisons of Large Birds

Argentine Teratorn(Argentavis magnificens)

California Condor (Gymnogyps californianus)

Merriam’s Teratorn (Teratornis merriami)

Wandering Albatross (Diomedae exulans)

60 cm (23.5”)

How Large Can a Soaring Bird Become ?

Argentine Teratorn(Argentavis magnificens)

Miocene 7 Mya

California Condor

Scale (m)

0 1

5.5 – 7.3 m (~18-24 ft.)

Ref. Campbell, K.E., Jr. and Tonni, E.P. (1983) Auk, Vol. 100, pp. 390-403.

Flight Muscle Mass as a Fraction of Total Mass in Birds

Flight muscle mass (MFM) = 0.25 M

Total Mass – M (kg)

Flight MuscleMass –

MFM (kg)

Power Requirements in Steady, Level Flight(According to the Square-Cube Law)

Power – P(watts)

Mass – M (kg)

“Pigeon”

Kori Bustard (20 kg)Ardeotis kori

Argentavis magnificens( circa 100 kg ?)

Including Reynolds Number Scale Effects in the Context of the Square - Cube Law

In steady level flight: Weight (W) = Lift ( L) = ½ρ V2CLS Thrust (T) = Drag (D) = ½ρV2CDS

CD = [CD f + CL2/πAR e] , CL < CL max , CD f ~ f (Re )

Reynolds number (Re) = ĉV/ν = [(2/ρν2) (W/CLAR) ]½ , AR = b2/S = b/ĉ

By the square-cube law: Wing span (b) and avg. chord (ĉ) ~ W1/3, Wing area (S) ~ W2/3, etc.

Power required (Preq ) = T x Speed (V) = WV(CD / CL) ≤ Pavailable

It then may be shown (e.g. via simple non-linear optimization techniques like geometric programming) that if CD f ~ Rem, the minimum power required varies as:

Minimum Preq ~ (M) r where r = 14 + 5m/ 3(4+m)

No scale effect (m = 0): r = 7/6 = 1.1667 Turbulent flow scaling (m = -1/5): r = 65/57 = 1.1404 Laminar flow scaling (m = -1/2): r = 23/21 = 1.0952

Mass (M) = W / g

Power Requirements in Steady, Level Flight(According to the Square-Cube Law)

Power – P(watts)

Mass – M (kg)

“Pigeon”

Kori Bustard (20 kg)(after Pennycuick)

Aiolornis [Teratornis] incredibilis(after H. Howard)

(35 kg)

P ~ M 65/ 57

(accounting forviscous scale

effects)

7/6 = 1.167

65/ 57 = 1.140

The perennial engineering question:

“Well, that’s all very interesting

I suppose but…..

What do you DO with it ?”

[ “Design better butterflies?” ]

The Transport Economy Index –Why Fly? Energy Consumed [E] per Unit Weight [W] per Unit Distance Traveled [R]

OptimumTransportEconomy

Index(cal/g-km)

100

10

1

0.1Improving

10 –6 1 10 6

Mass – M (kg)

Walker & Runners

Machines

Fliers

Swimmers

SUV

E/WR = P/WV

P = P0 + TV = CM0.74 + TV

T/W = (L/D )-1

Speed costs!

Future airplanes

?

P0 = basal metabolism for animals

The Cost of Speed (Gabrielli and von Kármán, 1950)

Improving

TechnologyDependent

i.e. Minimum energy consumed per unit weight per unit distance traveled for travel at a given speed.

?

Year

ProductivityIndex

V x U/W(mph)

0

1000

1900 20001920 1940 1960 1980

?

Sonic Cruiser

Boeing Trimotor

DC-3

DC-6

707

ConcordSST

747

757/67

777

OPEC

V = cruise speed (mph)W = gross weightU = useful load (fuel, passengers, freight)

One Measure of Progress in Civil Aeronautics

So Now What: Farther? Faster?….”Better”?

787

“TechnologicalImperative”(based in an

unlimited supply of cheap fuel)

??

Boeing’s Sonic Cruiser

Flying as fast as possible without creating a sonic boom.

Which Way to Go (circa 2002) ?“Farther, faster, higher” versus “Leaner, greener”

Fuel Burn,Direct

Operating Cost, etc.

1.0Cruise Mach Number

B 777

SSTB 767 (1980)

In the stratosphere (h > 36K ft.):Mach 0.01 ≈ 6.7 mph ≈ 11 km/hr

0

Future ??

Foundational R&D advances

B 707 (1960)

“Life’s too short to spend time working on Propellers”

Ed WellsThe Boeing Company

Or is it ??

German eta Sailplane(circa 1999 - present)

Wing Span (b) = 101.4 ft. (30.9 m)

Aspect Ratio (AR) = 51 L/D max ≈ 70 (est.)

“Altostratus” Sailplane 1/5-Scale Model for Permanent Displayed in the Smithsonian National Air & Space

Museum Udvar-Hazy Center at Dulles International Airport, Wash. DC – October 2004

Originally designed by John McMasters circa 1980Model constructed by Gary Fogel and Chris Silva in 2001

A “solar powered” concept airplane intended to achieve near 100% laminar flow on both the wing upper and lower surfaces – with a resulting theoretical maximum L/D approaching 100.

Cover of Feb.1981 issue of Soaring magazine. Painting by the late Boeing artist/illustrator, Jack Olsen.

Current Generation Undersea Gliders

W

B

Weight [W] (gravity) and Buoyancy [B] provide the motive forces.

V

D L

LD

Sea Trials began in April 2004 –

Measured glide angle of 17:1 (4/29/04). This compares with values of 5-7 for current generation

vehicles of this type.

Funded by the Office of Naval Research

Boeing/McMasters 29% thick airfoil

Scripps “Stingray” Undersea Glider

Scripps “X-Ray” Undersea Glider (2005)

Bionics Process Flow for Devices of Similar Operational Type

Nature Technology

Organism(Plant/Animal)

InitialBaseline Machine

Operational DesignRequirements and

Objectives (DR&Os)

Observe/DeduceOperationalRequirements

Observe/ Measure Physical Characteristics

Physical Characteristics

BasicKnowledge(Physics &Economics)

Understanding• How the organism works• What its devices do• Limitations

Define ImprovementsNeeded or Wanted

Borrow Concepts(not necessarilythe same hardwaresolutions)

Synthesize (Engineer)Solution(s)

Improved Baseline Machine ?

Evaluate/analyze

EvaluateAgainstDR&O

NASA/DARPA Morphing Aircraft Programs

The Very Variable Geometry of Bird Wings

Hunt: soar, observe Attack: dive, maneuver Soar and Search Stoop and Kill

Consequences of the Variable Geometry of a Bird Wing on Gliding Performance

Horizontal Speed V Vertical Speed(Sink rate)

+

0

How Much “Morphing” Is Enough ?

Tupolev Tu 160 “Blackjack” Bomber

Morphing Airplane Concepts – A Taxonomy ?

• “Static” Morphing – Several possible configurations from the same basic “root stock”, but once a choice is made you have to go with what you’ve got.

– Insects and anemophilous seeds– Variable mass (water ballast in sailplanes)

• “Dynamic” Morphing – Configuration changes as the situation or (sub-) mission changes.

– The usual “mission adaptive wings” (birds, F-111, F-14, B-1, etc.)– Flying cars/roadable airplanes– Flying submarines/submersible airplanes

• “Operational” Morphing - Either fixed or variable geometry platforms that may alter their capability by changing operational modes or by acting collectively.

– Colonial slime molds– Birds (formation and flocking flight)– Surface effects vehicles (wings in ground effect*)

John’s “Coil Wing” Morphing Airplane Concept(Continuously variable span, area and perhaps camber)

“High speed”(Small span and area)

“Low speed/Long endurance”(Large span and area [with increased camber?])

Asymmetric extension provides roll control

Rear (Trefftz Plane) Views

Probable maximumfeasible wing span ~ 30 cm.

John McMastersNovember 20, 2002

Vortices and Formation Flight

A “convoy” of C-17s

A Whole Flock of UCAVs(The Formation Flight of UCAVs Across the World in the Spring)

Cruise – good endurance Attack – high speed

beffective

b

Flight Direction (cruise)