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Expanding the range of possibilities-Biomimetics
Airplane Design: Past, Present and Future – An Early 21st Century Perspective
John H. McMastersTechnical Fellow
The Boeing [email protected]
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)