1

Agricultural Unmanned Aircraft System (AUAS)Team Two-CAN

Albert Lee (TL)Jacob NiehusAdam KuesterChris CironeMichael ScottKevin Huckshold

2

Presentation Overview• Configuration Selection (KH)• Initial Sizing (KH)• Constraint Analysis (CC)• Performance (CC)• Aerodynamics (AL)• Propulsion (MS)• Stability and Control (JN)• Structures (AK)• Configuration (KH)• Cost (MS)• Conclusion (AL)

Huckshold 3

Configuration Selection• Conventional• Canard• Biplane• Tandem Wing• Blended Wing Body• Flying Wing• Joined Wing

Huckshold 4

Configuration Selection

Final Three Configurations

Conventional Canard + Tractor Canard + Pusher

Huckshold 5

Initial Sizing• Initial weight sizing model was the same for all

three configurations– Take-off Gross Weight = 800lb– Empty-weight fraction = 0.54– Fuel-weight fraction = 0.049

Cirone 6

Constraint Analysis

(11.5, 0.1)

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

0.2

0 5 10 15 20 25

(W/S)o (lbf/ft2)

(P/W)o

Take-off ConstraintCruise ConstraintSustained Turn ConstraintLanding ConstraintDesign Point

Cirone 7

PerformanceChris Cirone

Cirone 8

Performance Overview

• Take Off Analysis• Cruise Analysis

– Turn Analysis• Mission Time• Fuel Consumption

•“2007 – 2008 AIAA Undergraduate Team Aircraft Design Competition,” AIAA, 2007.

Cirone 9

Take Off Analysis• RFP Constraint: 750 ft assumed total ground roll allotment.• Team Constraint: No high lift devices.• Approach: Find necessary CL,TO and corresponding VTO .

• Assumptions– Friction coefficient for grass airfield.– Ideal Thrust. (T=P*η/V, and max P for take off)– Drag form drag polar. (From Aerodynamics)– Maximum Take Off Weight. (From Configurations)

Take Off Parameters Conventional Tractor Canard Pusher Canard

Minimum CL,TO 0.934 0.977 0.978

Maximum VTO 68.8 mph 68.1 mph 68.0 mph

Factor of Stall Speed 1.24 1.21 1.21

Cirone 10

Cruise Analysis• Description:

– Spray Operation• Steady level flight at 20 ft AGL• Vop=1.3*Vstall

– Turn• Sustained turns

• Strategy: Determine most efficient spray pattern.– Race-track pattern with turns on short ends

• Minimize number of turns• Permits short half turns

Cirone 11

Cruise Analysis

– Maximize turn radii to limit load factors and high speeds• 33 Passes• 30.3 ft Swath• 257.6 ft & 242.4 ft Turn Radii• 21.3 mi cruise distance

– Land on opposite side of field• Maximizes both major and minor turn radii

Cirone 12

Turn Analysis• Priority: Validate the possibility of making the desired turns.

Cirone 13

Mission Time & Fuel Consumption• Cruise Mission Time

– Range: 21.26 mi – Spray legs Vop= 72.2 mph– Turns CL,stall

– Constant Weight– 17.6 minutes

• Fuel Estimation– RFP requirement: 20 minutes of reserve fuel– Using a maximum specific fuel consumption – Cruise: 7.818 lbs– Reserve fuel: 8.890 lbs (Vmin,power = 60.4 mph)– 2.2 Gallons Total

Cirone 14

Future Work in Performance• Climb Analysis• Dynamic Weight Model• Enhancement of Take Off and Turn Analysis

– Include improved thrust model• Update Mission Time and Fuel Consumption

– Include all mission segments– Include improved fuel consumption model

Lee 15

AerodynamicsAlbert Lee

Lee 16

Aerodynamics Overview• Airfoil Selection• Wing Characteristics• Drag on the Plane• Coefficients for Each Mission Segment• Lift-Drag Polars

Lee 17

Airfoil Selection• NACA 1412• Simple geometry, little camber• Cl,max=1.6, αCL,max=16°• t/c=12%

Anderson, J. D., Introduction to Flight, 5th ed., McGraw Hill, New York, 2005.

http://www.ae.uiuc.edu/m-selig/ads/coord_database.html

x

Lee 18

Wing Characteristics• Rectangular wing• Sref=69.6ft2

• AR=6• CL,max=1.44, αCL,max=19°• Oswald span efficiency e=0.87

Lee 19

Drag on the Plane• Calculated parasite drag using the form factor method

outlined in Raymer

Conventional Canard w/ Tractor Canard w/ Pusher

Component CD0 CD0 CD0

Wing 0.0070 0.0070 0.0070

Horizontal Tail 0.0021 0.0027 0.0019

Vertical Tail 0.0012 0.0016 0.0028

Fuselage 0.0043 0.0048 0.0047

Landing Gear 0.0081 0.0094 0.0099

Spray Boom 0.0046 0.0046 0.0046

TOTAL 0.0272 0.0301 0.0309

CD,L&P (% of total) 10 10 10

CD0 0.0299 0.0331 0.0340

Lee 20

Coefficients for Each Mission Segment

CL CDo CD L/D

Takeoff 0.93 0.030 0.054 17.3

Cruise 0.85 0.030 0.074 11.5

Turn 1.44 0.030 0.156 9.2

Landing 1.23 0.030 0.123 10.0

CL CDo CD L/D

Takeoff 1.00 0.033 0.069 14.5

Cruise 0.85 0.033 0.077 11.0

Turn 1.44 0.033 0.159 9.0

Landing 1.23 0.033 0.126 9.8

CL CDo CD L/D

Takeoff 1.00 0.034 0.067 14.9

Cruise 0.85 0.034 0.081 10.4

Turn 1.44 0.034 0.170 8.5

Landing 1.23 0.034 0.134 9.2

Conventional

Canard w/ Pusher

Canard w/ Tractor

Lee 21

Lift-Drag Polars

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

-1 -0.5 0 0.5 1 1.5

CL

C D

ConventionalCanard w/ Tractor

Canard w/ Pusher

Lee 22

Future Work in Aerodynamics• Develop CFD analysis method to get more

accurate wing performance data• Look into methods of providing more lift while

minimizing drag, size and weight.

Scott 23

PropulsionMichael Scott

Scott 24

Propulsion Overview• Motor Selection• Propeller Sizing• Engine Cooling System• Fuel System• Future Work

Scott 25

Motor Selection• 17 motors down selected to 4• Historical agricultural aircraft power loading

11 lbf/hp – 72.7 hp needed

70 250075 600081 580085 3300

Rotax (912 UL DCDL)Jabiru Aero Engine (2200A)

Zoche Aero-diesels (ZO 03A)UAV Engines Ltd (AR682)

RPMEnginePowermax

(HP)

Scott 26

0

50

100

150

200

250

300

350

400

450

500

0 10 20 30 40 50 60 70 80 90 100

Velocity (mph)

Thru

st (l

bf)

Zoche AeroUAV EnginesJabiru AeroRotax

Thrust-Velocity Curve at Maximum RPM

Scott 27

Propeller Sizing• Historical single engine aircraft disk loading

3 hp/ft2 – 8 hp/ft2

• Fixed pitch, 3 bladed propeller• Maximized blade length without tip reaching sonic velocity• Implemented gear box to reduce propeller RPM

0.80 22 0.309 3.000.65 10 0.320 2.440.63 12 0.341 2.360.70 20 0.333 2.63

Engine

Zoche Aero-diesels (ZO 03A)UAV Engines Ltd (AR682)Jabiru Aero Engine (2200A)

Rotax (912 UL DCDL) w/GB

ήp,maxPitch (deg)

Chord (ft)

T/hp (lb/hp)

Scott 28

Engine Cooling System• Down-draft vs. Up-draft• Entrance area directly related to

horsepower• Exit area set at 80% the entrance

area and expandable to 200%

Fuel System• Fuselage fuel tank - 7 gal.

- Reduce wing structure

- Ease to manufacture and maintain

• At cruise – 75% throttle- ZO 03A 2.7 gal/hr- 2200A 4.0 gal/hr- 912 UL 6.3 gal/hr- AR682 6.7 gal/hr0.32

0.340.390.37

A (ft2)Engine

Zoche Aero-diesels (ZO 03A)UAV Engines Ltd (AR682)Jabiru Aero Engine (2200A)

Rotax (912 UL DCDL) w/GB

Scott 29

Future Work in Propulsion• Detailed motor analysis over

throttle range• Motor down select• Motor mounting• Actual propeller data• Detailed air intake analysis• Detailed fuel consumption

Niehus 30

Stability and ControlJacob Niehus

Niehus 31

Stability and Control Overview

• Determine tail and control surface geometry for adequate controllability

• Determine center of gravity location for longitudinal static stability

• RFP requirement: “ease of operation”

Niehus 32

Tail Sizing Method• Tail volume coefficient method

• Values found from historical correlations• Control surface sizing from historical

dimensions

cSSl

Vref

hhh =

ref

vvv bS

SlV =

Niehus 33

Tail Sizing Trade Study

0.00

5.00

10.00

15.00

20.00

25.00

30.00

5 7 9 11 13 15

Distance between center of gravity and horizontal stabilizer (ft)

Plan

form

are

a of

hor

izon

tal s

tabi

lizer

(ft^

2)

Niehus 34

Tail Sizing Results

Niehus 35

Longitudinal Stability Method• Neutral point is the location at which pitching

moment is constant with angle of attack

• Empirical values from methods in Raymer• Center of gravity must fall in front of neutral

point for positive static stability• 2%<SM<15%

ref

pach

hL

ref

hhL

pp

ref

pach

hL

ref

hhfusmacwL

np

qSF

XCSS

C

XqSF

XCSS

CXCX

h

h

α

αα

α

αα

αα

η

αα

αα

ηα

+∂∂

+

∂

∂+

∂∂

+−

=

Niehus 36

Longitudinal Stability Trade Study

0.72

0.73

0.74

0.75

0.76

0.77

0.78

0.79

0.80

0.81

0.82

0.83

5 7 9 11 13 15

Distance between center of gravity and horizontal stabilizer (ft)Neu

tral

poi

nt lo

catio

n be

hind

win

g qu

arte

r-ch

ord

(ft)

Niehus 37

Longitudinal Stability Results

Conventional Canard-Pusher Canard-Tractor

Neutral Point

(ft) 0.78 -2.05 -2.06

(ft) 0.71 -2.12 -2.13Center of Gravity Limits for Stability (ft) 0.27 -2.56 -2.57

npX

aftcgX

forwardcgX

Niehus 38

Future Work in Stability and Control• More detailed control surface sizing analysis• Lateral and directional static stability• Dynamic stability in all axes

Kuester 39

StructuresAdam Kuester

Kuester 40

Structures Overview• V-n diagram and load factor• Materials selection• Aircraft structure• Wing structure• Landing gear• Future work

Kuester 41

V-n Diagram• Design load

factors

• Effect of a more symmetric airfoil

• Nearly identical for conventional and two canards

0 10 20 30 40 50 60 70 80 90 100

-2

-1

0

1

2

3

4

Velocity (mph)

Load

Fac

tor n

Design Load Cruise Gust Load Dive Gust Load Maneuver Load

D

A

E

B

C

Kuester 42

Materials Selection• Consider durability and cost

– Wood • Performance in weather

– Composites• Costs

– Steel• Heavy but strong

– Aluminum• Lighter and commonly

used

• Primarily aluminum– Steel and composite

use

Specific Yield Strength

Wood 8.75 750

Carbon Fiber Composites 52.5 8000

Stainless Steel Alloys

(15-5PH)10 500

Aluminum Alloys(7075)

10 700

43

ksi x10lbm/in

/E ρ⎛ ⎞⎜ ⎟⎝ ⎠ 3

ksilbm/in

⎛ ⎞⎜ ⎟⎝ ⎠

Properties of Various Aircraft Materials

Kuester 43

Aircraft Structure

• Longerons carry bending and axial loads• Bulkheads located at concentrated loads

– Landing gear, hopper, wing spar carrythrough• Stressed skin carries shear and torsional loads

Kuester 44

Wing Structure• Wing box carrythrough

– Most unobtrusive option– Easiest construction

• Wing structure– Two spars

• Quarter chord and aileron support

• Folding Wing– Common in general aviation– Hinge towards rear of wing– One or two person job Cessna Mustang with Folded Wings

http://www.mustangaero.com/Mustang%20II/FoldingWing.html

Kuester 45

Landing Gear • Conventional and Canard Tractor– Taildragger

• Solid spring main gear• Castoring tail wheel

• Canard Pusher– Tricycle

• Solid spring main gear• Oleo strut front gear

– Prop strike• Wheel sizing

– 5.00-5 tires• Common on light aircraft

Distance Ahead of CG

(ft)

Distance Below CG

(ft)

Conv. 1.4 3.8

Canard Tractor 1.45 4

Canard Pusher -1 2.9

Kuester 46

Future Work in Structures• Fuselage structure

– Determine shape, size, and material of members– Minimize structural weight

• Wing structure– Determine internal structure of ribs, spars, and ailerons– Finalize folding wing design

• Landing gear– Finalize placement, general dimensions, and tire size

• Insure durability of aircraft

Huckshold 47

ConfigurationKevin Huckshold

Huckshold 48

Configuration Objectives• Estimate aircraft weight• Determine internal/external layout• Track CG location throughout mission• Develop CAD model

Huckshold 49

Weight Buildups• Aircraft weight a sum of component group weights, defined by Raymer

Equn. 15.46-59• Component weights a function of geometry, other known constants, based

on historical data

– ie, wing weight = f (Sw, AR, sweep angle, dynamic pressure, thickness ratio, load factor, TOGW)

• Components modeled (in addition to payload, fuel):

• TOGW (lbs) for heaviest payload: Conventional: 771.3, Canard/Pusher: 811.0, Canard/Tractor: 811.5

Wings Installed engine

Fuselage Fuel system

Tail/Canard Surfaces Flight controls, hydraulics

Landing gear Electrical system

Huckshold 50

Configuration

• Wing and empennage sizes, positions relative to CG given by Aero, S&C

• Landing gear location given by Structures• Most other component locations constrained- ie, flight controls must go

on wings, etc.• Motor must go in front (tractor) or in back (pusher)• Challenge- place few remaining components to move CG to desired

location, this defines fuselage length

Huckshold 51

Center of Gravity• Per S&C, 2-15% Static Margin acceptable• CG locations calculated for varying amounts of fuel

– No payload (blue)– Wet payload -235 lbs (red)– Dry payload -300 lbs (green)

Canard/Pusher

0

10

20

30

40

50

60

70

80

90

100

0246810121416

Static Margin (%)

Fuel Le

vel (%

)

Canard/Tractor

0

10

20

30

40

50

60

70

80

90

100

0246810121416

Static Margin (%)

Fuel Le

vel (%

)

Conventional

0

10

20

30

40

50

60

70

80

90

100

0246810121416

Static Margin (%)

Fuel Le

vel (%

)

Huckshold 52

Internal Layout

Motor (2.38 x 1.82 x 1.5 ft.)

Battery (~1 x 1 x 1 ft.)

Pump (2 ft. OD sphere)

Hopper (1.87 ft. x 2 ft. OD)

Fuel Tank (7 gallons- 1.37 x 1.37 x 0.5 ft.)

Fuselage diameter: 2.5 ft.

Tail (tractor)/Nose (pusher) cone length: 6 ft.

Huckshold 53

Huckshold 54

Huckshold 55

Huckshold 56

Future Work in Configuration• Develop more accurate component-based

weight buildup• Continue refining layout, reduce fuselage

length if possible• Calculate vertical CG location, envelope as

payload empties• Calculate moments of inertia

Scott 57

Cost Analysis• Conventional configuration is cheapest• Costs of canards are approximately equal

Fabric Aluminum Composite Fabric Aluminum Composite23550 27450 31150 24950 28850 3255024150 28200 32050 25550 29600 3345024150 28200 32050 25550 29600 33450

Fabric Aluminum Composite Fabric Aluminum Composite28650 32550 36250 27000 30900 3460029250 33300 37150 27600 31650 3550029250 33300 37150 27600 31650 35500

UAV Engines Ltd (AR682)

Conventional/TractorCanard/Tractor

Jabiru Aero Engine (2200A) Rotax (912 UL DCDL)

Canard/Pusher

Zoche Aero-diesels (ZO 03A)

Conventional/TractorCanard/Tractor

Canard/Pusher

Lee 58

Conclusion• Leading configuration: Conventional with

Zoche diesel engine– Cheapest and lightest configuration– Best performance due to lower drag and more

efficient propulsion system– Smallest configuration

• Future Work– Develop more detailed analysis methods– Optimize airplane performance

59

References• [1] “2007 – 2008 AIAA Undergraduate Team Aircraft Design Competition,”

AIAA, 2007.

• [2] Raymer, D. P., Aircraft Design: A Conceptual Approach, 4th ed. AIAA, Reston, VA, 2006.

• [3] Sobester, A., Keane, A., Scanlan, J., and Bresslof, N., “Conceptual Design of UAV Airframes Using a Generic Geometry Service,” AIAA 2005-7079, September 2005.

• [4] Anderson, J. D., Introduction to Flight, 5th ed., McGraw Hill, New York, 2005.

• [5] Bernard Hooper Engineering Ltd [online], http://users.breathe.com/prhooper/ [retrieved 7 November 2007].

• [6] “The Engine Specifications,” Hpower-Ltd [online], http://www.hpower-ltd.com/pages/specifications.htm [retrieved 7 November 2007].

• [7] “Limbach L1700 EA, L2000 EA, L2400 EB, Limbach Flugmotoren [online], www.limflug.de[retrieved 7 November 2007].

60

References• [8] “Zoche Aero-diesels Specifications,” Zoche [online],

http://www.zoche.de/specs.html [retrieved 7 November 2007].

• [9] “Mikron IIIB,” Moravia Inc [online], http://www.moraviation.com[retrieved 7 November 2007].

• [10] UAV Engines [online], http://www.uavenginesltd.co.uk [retrieved 7 November 2007].

• [11] Rotax Aircraft Engines [online], www.rotax-aircraft-engines.com[retrieved 7 November 2007].

• [12] “Jabiru 2200 4 Cylinder 85bhp,” Jabiru Aircraft Engines [online], http://www.jabiru.co.uk/engines.htm [retrieved 7 November 2007].

• [13] “HAE-100 Data Sheet 2,” Howell Aero Engines Limited [online], http://www.howells-aeroengines.co.uk/D2.html [retrieved 7 November 2007].

• [14] “235 Cubic Inch Engine Series,” Lycoming Engines-A Textron Company [online], http://www.lycoming.textron.com/ [retrieved 7 November 2007].

61

References• [15] “DAIR-100 Technical Features,” FTI Diesel Tech, LLC [online],

http://www.dieseltech.cc/techfeatures.htm [retrieved 7 November 2007].

• [16] Kroo, Ilan. "Tail Design and Sizing." Aircraft Aerodynamics and Design Group. Stanford University. 12 Nov. 2007 http://adg.stanford.edu/aa241/stability/taildesign.html.

• [17] Chiles, I., “Structures: V-n Diagrams,” AE 440-A Course Notes, URL: http://courses.ae.uiuc.edu/AE440-A/files/StructuresRefresher.pdf, 2007 [retrieved 13 November 2007].

• [18] Federal Aviation Administration, “FAR Part 23,” Federal Aviation Regulations [online], URL: http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgFAR.nsf/MainFrame? OpenFrameSet [retrieved 14 November 2007].

• [19] Megson, T. H. G., “Principles of Stressed Skin Construction,” Aircraft Structures for Engineering Students, 3rd ed., Butterworth-Heinemann, Oxford, England, 1999, pp. -211-232.

• [20] Broeren, A. P., “Conceptual Design Report-Preliminary Cost Model,” AE440 Aerospace Systems Design I, [handout], 11 October 2007.

62

Any Questions?