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
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
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...
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 2 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
LONG STORY SHORT !
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 3 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
LONG STORY SHORT !
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 3 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
WHERE LONG ENDURANCE MINI UAV BELONGS
Size [m]
Endurance [hours]
1 10 100
1
10
100
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 4 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
WHERE LONG ENDURANCE MINI UAV BELONGS
Size [m]
Endurance [hours]
1 10 100
1
10
100
BlackWidowWasp
Raven
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 4 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
WHERE LONG ENDURANCE MINI UAV BELONGS
Size [m]
Endurance [hours]
1 10 100
1
10
100
BlackWidowWasp
Raven
Mini-Micro
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 4 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
WHERE LONG ENDURANCE MINI UAV BELONGS
Size [m]
Endurance [hours]
1 10 100
1
10
100
BlackWidowWasp
Raven
GlobalHawk
PredatorSkySailor
LunaX
Aerosonde
Mini-Micro
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 4 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
WHERE LONG ENDURANCE MINI UAV BELONGS
Size [m]
Endurance [hours]
1 10 100
1
10
100
BlackWidowWasp
Raven
GlobalHawk
PredatorSkySailor
LunaX
Aerosonde
Long-Endurance
Mini-Micro
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 4 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
WHERE LONG ENDURANCE MINI UAV BELONGS
Size [m]
Endurance [hours]
1 10 100
1
10
100
BlackWidowWasp
Raven
GlobalHawk
PredatorSkySailor
LunaX
Aerosonde
Long-Endurance
Mini-Micro
Long-EnduranceMini UAV
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 4 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
OUTLINE
1 INTRODUCTION
2 DESIGN METHODOLOGY
3 CASE STUDY : ETERNITY
4 CONCLUSION
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 5 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
OUTLINE
1 INTRODUCTION
2 DESIGN METHODOLOGY
3 CASE STUDY : ETERNITY
4 CONCLUSION
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 6 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY 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
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
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
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 8 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
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
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 9 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
CDSGN FLOW CHART
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 10 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
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)
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 11 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
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.
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 12 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
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
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
REQUIRED MODIFICATIONS TO AVL
Viscous drag addition for the lifting surfaces (via Xfoil)Stall informationFuselage viscous dragVerification and calibration of the modifications
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 13 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
VISCOUS DRAG IMPLEMENTATION
Lift distribution obtained from AVLCorresponding local drag coefficients from polarsAirfoil polar database generated by Xfoil for each Reynolds
AVL Calculation
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 14 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
VISCOUS DRAG IMPLEMENTATION
Lift distribution obtained from AVLCorresponding local drag coefficients from polarsAirfoil polar database generated by Xfoil for each Reynolds
Lift Distribution
AVL Calculation
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 14 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
VISCOUS DRAG IMPLEMENTATION
Lift distribution obtained from AVLCorresponding local drag coefficients from polarsAirfoil polar database generated by Xfoil for each Reynolds
Cl
Cd
Cl Cl
Cd
ClCl
Cd
Cl
Lift DistributionLocal Lift and Drag
Coefficients
AVL Calculation
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 14 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
VISCOUS DRAG IMPLEMENTATION
Lift distribution obtained from AVLCorresponding local drag coefficients from polarsAirfoil polar database generated by Xfoil for each Reynolds
Cl
Cd
Cl Cl
Cd
ClCl
Cd
Cl
Lift DistributionLocal Lift and Drag
Coefficients
Viscous Drag Distribution
AVL Calculation
Local viscous drag coefficients are
integrated
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 14 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
STALL DETECTION
Cl
Cd
Cl Cl
Cd
ClCl
Cd
Cl
Lift DistributionLocal Lift and Drag
Coefficients
AVL Calculation
STALLED STRIP
ClmaxCl required> × Coeff
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 15 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
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
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 16 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
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
Wind Tunnel
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 16 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
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
AVLM 8 m/s
Wind Tunnel
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 16 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
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
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 17 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
OUTLINE
1 INTRODUCTION
2 DESIGN METHODOLOGY
3 CASE STUDY : ETERNITY
4 CONCLUSION
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 18 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY 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
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 19 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
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
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 20 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
CONFIGURATION SELECTION
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
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 20 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
CONFIGURATION SELECTION
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
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 20 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
CONFIGURATION SELECTION
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
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 20 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
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
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 21 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
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
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 21 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
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
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 22 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
FINAL APPEARANCE
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 23 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
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
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
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.
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 25 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
OUTLINE
1 INTRODUCTION
2 DESIGN METHODOLOGY
3 CASE STUDY : ETERNITY
4 CONCLUSION
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 26 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY 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
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 27 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
CONCLUSION AND PERSPECTIVE
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
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 27 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
CONCLUSION AND PERSPECTIVE
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
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 27 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
Thank you very much for your [email protected]
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 28 / 29
INTRODUCTION DESIGN METHODOLOGY CASE STUDY : ETERNITY CONCLUSION
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.
Murat Bronz (ENAC) Desig of Long Endurance Mini-UAVs October 2014 29 / 29