Desig of Long Endurance Mini-UAVs - w3.onera.frw3.onera.fr/aerial-robotics2014/sites/w3.onera.fr.aerial-robotics... · Design of Long Endurance Mini-UAVs ... characteristics of a

INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION

Design of Long Endurance Mini-UAVs

Murat Bronz1 Jean-Marc Moschetta2

l’Ecole National de l’Aviation Civil, Toulouse, France

Institut Superieur de l’Aeronautique et de l’Espace, Toulouse, France

Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 1 / 29


MOTIVATION

Why Long Endurance Mini UAV ?

Operational EffectivenessLow-costNo need for complicated launching system...

Potential ApplicationsCoastal or border surveillanceAtmospheric and weather research and predictionEnvironmental, forestry and oceanic monitoringMapping and imaging for the media and industries...



LONG STORY SHORT !



LONG STORY SHORT !



WHERE LONG ENDURANCE MINI UAV BELONGS

Size [m]

Endurance [hours]

1 10 100

1

10

100




Size [m]

Endurance [hours]

1 10 100

1

10

100

BlackWidowWasp

Raven




Size [m]

Endurance [hours]

1 10 100

1

10

100

BlackWidowWasp

Raven

Mini-Micro




Size [m]

Endurance [hours]

1 10 100

1

10

100

BlackWidowWasp

Raven

GlobalHawk

PredatorSkySailor

LunaX

Aerosonde

Mini-Micro




Size [m]

Endurance [hours]

1 10 100

1

10

100

BlackWidowWasp

Raven

GlobalHawk

PredatorSkySailor

LunaX

Aerosonde

Long-Endurance

Mini-Micro




Size [m]

Endurance [hours]

1 10 100

1

10

100

BlackWidowWasp

Raven

GlobalHawk

PredatorSkySailor

LunaX

Aerosonde

Long-Endurance

Mini-Micro

Long-EnduranceMini UAV



OUTLINE

1 INTRODUCTION

2 DESIGN METHODOLOGY

3 CASE STUDY : ETERNITY

4 CONCLUSION



OUTLINE

1 INTRODUCTION



4 CONCLUSION



PUSHING THE LIMITS ?

With the traditional design method, there is no way to push the limits !

The Voyager’s 1 structural weight is only %9.7 of its total take-offweight.

1http : //en.wikipedia.org/wiki/Rutan VoyagerMurat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 7 / 29


CONCEPTUAL DESIGN PROGRAM (CDSGN)

CdsgnMain objective of Cdsgn program is to calculate the aerodynamiccharacteristics of a configuration in an accurate and fast way tocompare with different configurations.

Creates GENERIC aircraft configurations by :Wing span dimensionReference surface areaReference coefficients and constants



CDSGN FLOW CHART

-Mission Convergence-Mission Scoring-Filtering

Structure System Weight Battery

Motor Weight

Total WeightSolar System

Generate Aircraft

Generate RUN File

RUN AVL

Performance

Check Convergenge

Neu

tral P

oint

Mot

or W

eigh

tOUT

IN Aircraft Configuration

AIRCRAFT GENERATION & MODELLING SIMULATION

-Configuration Type-Wing Span (Min,Max,Delta)-WingSurface(Min,Max,Delta)-Battery Cap. (Min,Max,Delta)-Structural Properties-Manufacturing Technique-Airfoil Database-Component Efficiencies-Desired Handling Qualities

……

Mission Definition (Scoring)

INPUT PARAMETERS

-Post Processing-Final Selection

STORE RESULTS



CDSGN FLOW CHART



PARTICULARITIES OF CDSGN

Two aircraft configurationsStructure model calibrated for MAVsComputationally fast aero-analyses with Reynolds number effectstaken into accountTrim analysisStall detection (Airfoil Clmax)Same longitudinal stability (via Static margin)



EXTERNAL PROGRAMS

XFOIL2 is a design and analysis program for subsonic isolated airfoils.Linear-vorticity stream-function panel method for the inviscidformulationThe boundary layers and the wake are described with atwo-equation lagged dissipation integral boundary layerformulation

2Mark Drela. An analysis and design system for low reynolds number airfoils. InUniversity of Notre Dame, editor, Conference on Low Reynolds Number AirfoilAerodynamics, June 1989.



EXTERNAL PROGRAMS

AVL2 is an open source program for the aerodynamic andflight-dynamic analysis of rigid aircraft.

Aerodynamic Analyses, with Vortex-Lattice MethodTrim CalculationsPredicts flight stability characteristics

2http : //web.mit.edu/drela/Public/web/avlMurat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 12 / 29


REQUIRED MODIFICATIONS TO AVL

Viscous drag addition for the lifting surfaces (via Xfoil)Stall informationFuselage viscous dragVerification and calibration of the modifications



VISCOUS DRAG IMPLEMENTATION

Lift distribution obtained from AVLCorresponding local drag coefficients from polarsAirfoil polar database generated by Xfoil for each Reynolds

AVL Calculation





Lift Distribution

AVL Calculation





Cl

Cd

Cl Cl

Cd

ClCl

Cd

Cl

Lift DistributionLocal Lift and Drag

Coefficients

AVL Calculation





Cl

Cd

Cl Cl

Cd

ClCl

Cd

Cl


Coefficients

Viscous Drag Distribution

AVL Calculation

Local viscous drag coefficients are

integrated



STALL DETECTION

Cl

Cd

Cl Cl

Cd

ClCl

Cd

Cl


Coefficients

AVL Calculation

STALLED STRIP

ClmaxCl required> × Coeff



REPRESENTATION OF VISCOUS EFFECTSComparison of wind tunnel measurements with modified and originalAVL program

0

2

4

6

8

10

12

14

16

18

20

0 2 4 6 8 10 12 14 16 18 20 22 24

Endura

nce

(C

L1.5

/CD

)

Range (CL/CD)

AVLINVISCID




0

2

4

6

8

10

12

14

16

18

20

0 2 4 6 8 10 12 14 16 18 20 22 24

Endura

nce

(C

L1.5

/CD

)

Range (CL/CD)

AVLINVISCID

Wind Tunnel




0

2

4

6

8

10

12

14

16

18

20

0 2 4 6 8 10 12 14 16 18 20 22 24

Endura

nce

(C

L1.5

/CD

)

Range (CL/CD)

AVLINVISCID

AVLM 8 m/s

Wind Tunnel



REPRESENTATION OF VISCOUS EFFECTSComparison of wind tunnel measurements with modified AVLprogram

0

0.05

0.1

0.15

0.2

0.25

0.3

-0.4 -0.2 0 0.2 0.4 0.6 0.8 1-10

-5

0

5

10

15

CD

CL/C

D a

nd C

L3/C

D2

CL

CDAvl

(CL/CD)Avl

(CL1.5

/CD)Avl

CD

CL/CD

CL1.5

/CD



OUTLINE

1 INTRODUCTION



4 CONCLUSION



DESIGN OF ”ETERNITY”

Design EnvelopeTwo different aircraft configurations (Conv and F-W)Solar and non-solar flight conditionsSpan (1 m)Various Surface Area (0.05− 0.2 m2)Various flight speed (8− 20 m/s)Various Battery Capacity (Li-Po 20− 210 Wh)Different Airfoils



CONFIGURATION SELECTION

Conventional configuration with BATTERY

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

0 1 2 3 4 5 6 7 8

Win

g A

rea

[m2]

Endurance [h]

0 100 200 300 400 500

Range [km]

Up to 6 hours of endurance




Flying-wing configuration with BATTERY

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

0 1 2 3 4 5 6 7 8

Win

g A

rea

[m2]

Endurance [h]

0 100 200 300 400 500

Range [km]

Hardly reaching 5 hours




Conventional configuration with SOLAR

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

0 1 2 3 4 5 6 7 8

Win

g A

rea

[m2]

Endurance [h]

0 100 200 300 400 500

Range [km]

8 hours of endurance without a big dependency on surface area




Flying-wing configuration with SOLAR

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

0 1 2 3 4 5 6 7 8

Win

g A

rea

[m2]

Endurance [h]

0 100 200 300 400 500

Range [km]

Can reach 8 hours of endurance with only certain surface area



ON BOARD ENERGY

Effect of on-board energy on endurance and range performance forNON-SOLAR conditions

0

20

40

60

80

100

120

140

160

180

200

220

0 1 2 3 4 5 6 7 8

On-B

oar

d E

ner

gy [

Wh]

Endurance [h]

0 100 200 300 400 500

Range [km]

A saturation on endurance after 140 Wh of on-board energy



ON BOARD ENERGY

Effect of on-board energy on endurance and range performance for SOLARconditions

0

20

40

60

80

100

120

140

160

180

200

220

0 1 2 3 4 5 6 7 8

On-B

oar

d E

ner

gy [

Wh]

Endurance [h]

0 100 200 300 400 500

Range [km]

Best endurance occurs around 50 Wh of on-board energy



AIRFOIL FAMILY

0 0.1 0.2 0.3 0.4 0.5

Span [m]

PKMB500PKMB601PKMB702PKMB803

0.0

0.5

1.0

1.5

0.00 0.02

Cl

Cd

Re√Cl=110k

0.00 0.02

Re√Cl=90k

0.00 0.02

Re√Cl=60k

0.00 0.02 0.04 0.06

Re√Cl=30k



FINAL APPEARANCE



FLIGHT TESTS

Flight tests have been performed by Delair-Tech3 UAV Company,within a cooperation project(MIDLE) between ENAC-ISAE-TTT.

3www.delair-tech.comMurat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 24 / 29


FLIGHT TESTS

Obtained ResultsClose to 10 hours of flight dataLongest flight being 2 hours and 7 minutes

I With an heavier version (+100g)I While doing several stall tests and flight speed changesI Using 81% of the battery energy (small battery pack)

Maximum L/D ratio of 13.9Maximum CL

1.5/CD of 13.0

Considering all the differences of the test configuration compared tothe design configurations, the flight test results act as a reference pointrather than a direct comparison.



OUTLINE

1 INTRODUCTION



4 CONCLUSION



CONCLUSION AND PERSPECTIVE

Remarks and ConclusionA design method (Cdsgn) has been developed and calibrated inorder to show the feasibility of designing long endurance miniUAVsIt is feasible that a mini UAV with only 1 m wingspan can fly 8hours




Size [m]

Endurance [hours]

1 10 100

1

10

100

BlackWidowWasp

Raven

GlobalHawk

PredatorSkySailor

LunaX

Aerosonde

Long-Endurance

Mini-Micro

Long-EnduranceMini UAV

Eternity

Storm




PerspectiveThe use of external energy sources such as thermals and windgusts for additional enhancement of the endurance performanceof the MAVControl laws taking into account the system power consumptionwhile compromising from the navigation accuracyOptimized navigation path planning for energy conservation



Thank you very much for your [email protected]



ETERNITY EXPECTED RESULTS

Small BigCruise Speed [m/s] 11.5 14.0Cruise Lift Coefficient [−] 0.71 0.76Stall Speed [m/s] 9.2 11.6Max Bank Angle at Vcruise [deg] 50.0 46.0Turn Radius at Max Bank [m] 11.3 19.3Battery capacity [Wh] 62.5 125Payload Mass [kg] 0.05 0.10Total Mass [kg] 0.85 1.35Solar ConditionsEndurance [h] 7.48 6.2Range [km] 309 312Non-Solar ConditionsEndurance [h] 3.3 3.92Range [km] 138 197

Table: Expected performance of the two Eternity configurations.


Desig of Long Endurance Mini-UAVs - w3.onera.frw3.onera.fr/aerial-robotics2014/sites/w3.onera.fr.aerial-robotics... · Design of Long Endurance Mini-UAVs ... characteristics of a

Documents