J. Philip Barnes May 2015 Aircraft Energy Gain From an Atmosphere in Motion 01-02 May, 2015 Santa...

J. Philip Barnes www.HowFliesTheAlbatross.com May 2015

Aircraft Energy Gain From an Atmosphere in Motion01-02 May, 2015 Santa Rosa, CA J. Philip Barnes

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Part I of 2:

How Flies the Albatross The Flight Mechanics of Dynamic Soaring 24 May 2015 J. Philip Barnes

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Presentation Contents ~ How Flies the Albatross

Observations

SimplificationAnalysis

Simulation The visionaries

Wind data


Presentation Contents

www.HowFliesTheAlbatross.comRoyal Albatross

“The albatross can maintain this swooping soaring flight for hours on end without a single wing beat.” -- David Attenborough

Observations of Well-known Naturalists“The albatross ….. manages to remain master of its own course, either carried ... around the globe or ... against the strong winds without a beat of its wings.” -- Jacques Cousteau

Quoting the Visionaries

Isaac Newton, Principia, 1725

Wellcomeimages.org

Lord Rayleigh, Nature, 1883

“Quantity of motion [momentum] is a measure...that arises from the velocity and the quantity of matter”

“A change in motion [acceleration] is proportional to the motive force.”

“Centripetal force is the force by which bodies are drawn from all sides...toward...a center.”

“ ... suppose that above and below a certain plane ... there is a uniform horizontal wind, but that ascending through this plane the [wind] velocity increases...”

“... energy at the disposal of the bird depends on his velocity relatively to the air” “....it is only necessary ... to descend ... to leeward, and ... ascend ... to windward.”


Moonroof & Model Airplane

90 km/hr

Wow! Now I understand dynamic soaring

Flight kinetic energy depends on airspeed, not groundspeed

well, say 50%.....

90 km/hr airspeed

90 km/hr groundspeed


Albatross GPS/INS-backpack velocity ~ equals ground speed

V

y

Vg

Localwind

w

Ground speed

VcosgAirspeed shadow

INS/GPS

“…relatively to the air…” - Lord Rayleigh

Nature, 05 April 1883

Lift & drag ~ airspeed squared.This sketch: INS/GPS velocity for K.E. yields error factor of 4

“Backpack” INS/GPS velocity is very close to groundspeed, but the bird is rarely aligned with its ground track

The bird is aligned with relative wind, representing its airspeed.


Wind speed data ~ Southern latitudesReal-time snapshotW, m/s @ 10 m elev.

Data courtesy of Department of Meteorology, University of Reading, UK – www.met.rdg.ac.uk

W, m/s


Wind profile ~ First Vs. updated estimates

The logarithmic profile is more representative and is founded on theory


Wind gradients compared ~ First Vs. updated estimates

Similar gradients, 1-to-6 m elevation


Dynamic Soaring ~ Force Diagram

Dynamic Soaring Force Vector (F)F = m(dw/dt), directed upwind

T = m (dV/dt) = m (dw/dt) (dV/dw) = m (dw/dt) cosg cosy = m (dw/dz) (dz/dt) cosg cosy = m w’ V sing cosg cosy

Dynamic Soaring Thrust , T = F∙V

Direct quantitative equivalent of Lord Rayleigh’s qualitative dynamic soaring description

Isolate dynamic soaring thrust(ignore weight & drag for now)

mg

f

y

g D

L

mwV

w

Wellcomeimages.org

Lord Rayleigh

www.HowFliesTheAlbatross.comBlack-browed Albatross


Three orthogonal accelerations ~ Newton’s Law Applied

V

Vcosgg

[Vcosg]y

y

TurnRadius

Isaac Newton

g LoopRadius

Vg

V


Schedule any two angles, say(g t) & (y t) ; get dg/dt, dy/dt

Eqns. yield all other parameters

Equations of motion ~ three orthogonal accelerations

LDnWTgVn nt //sin/

2

1

D/L (CDo /CL ) + CL /(3A) 6

CL = nn W / (½ V2 S) 5

cos

cossin/'cos/ 2gVwgV

W

Lnn

3

tancos/tan

sin-costansinw')V/(g

4

7

7: Trajectory

x = w – V cosg cos ydownwind

y = V cosg sin ycrosswind

z = V sing vertical

Thrustgroup

DraggroupL

Dn

L

D

W

L

W

Dn

6: Drag-to-lift ratio

5: Lift coefficient

4: Heading rate

1: Normal load factor

3: Tangent. load factor

2: Dimensionless drag


Sensor platform is maintained level


Maneuver Angle Schedules ~ Math-modeled Examples

0.00 0.25 0.50 0.75 1.00

0

4 Sin2 “adder”

0.00 0.25 0.50 0.75 1.00 1.25 1.50 1.75 2.00

-50

0

50

Bank Right

Bank Left

Bank AngleSchedule

-10

0

10Sine Wave

Heading or time/period

t1

0.0 0.5 1.0

t2

0.0

0.5

1.0

Dt

Midpoint Shift

Auxiliary Time, t1

t20.0 0.5 1.0

t3

0.0

0.5

1.0Endpoint “dwell”

Auxiliary Time, t2

0.0 0.2 0.4 0.6 0.8 1.0

-10

-5

0

5

10

15

Climb

Dive

Flight Path Angle Schedule

Heading or time/period


Real-time simulation

C:\Users\Philip\albatross\Algebratross_si

C:\Users\Philip\albatross\msvbvm50.dll

25J. Philip Barnes www.HowFliesTheAlbatross.com

0 20 40 60 80 100 1200

2000

4000

6000

8000

10000

12000

14000

16000

Horizontal Wind Vs. AltitudeH. Riehl, Jet Streams of the Atmosphere, CO State Univ. 1962

CompositeSeattleNorfolkFlorida

Wind speed, m/s

Altitude, m

Dynamic soaring in the jet stream

26Energy From an Atmosphere in Motion - Dynamic Soaring and Regen-electric Flight Compared J. Philip Barnes www.HowFliesTheAlbatross.com

Notional conditions• Altitude ~ 8.5 km• Mach ~ 0.85• L/D ~ 25

Basic feasibility test:w' (V/g) (L/D) sin g > 1

Dynamic soaring in the jet stream

Dynamic soaring thrust offsets drag overall in zoom cycle

Conclusion ~ How Flies The Albatross

Let not the albatross go extinct on our short watch

• Flight without flapping• Wind gradient, not windspeed• Airspeed, not groundspeed• Net progress, any direction• 50M-yr evolutionary opt.


About the Author

Phil Barnes has a Master’s Degree in Aerospace Engineering from Cal Poly Pomona. He is a Principal Engineer and 34-year veteran of air vehicle and subsystems performance analysis at Northrop Grumman, where he presently supports both mature and advanced tactical aircraft programs. Author of several SAE and AIAA technical papers, and often invited to lecture at various universities, Phil is presently leading several Northrop Grumman-sponsored university research projects including an autonomous thermal soaring demonstration, passive bleed-and-blow airfoil wind-tunnel test, and application of Blender 3D software for aircraft parametric geometry modeling and flight simulation. Outside of work, Phil is a leading expert on dynamic soaring, and he is pioneering the science of regen-electric flight.

J. Philip Barnes May 2015 Aircraft Energy Gain From an Atmosphere in Motion 01-02 May, 2015 Santa...

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