1. AAE 451 Team 3 Critical Design Review
Jon Amback
Melissa Doan
Stacie Pedersen
Kevin Badger
Jason Hargraves
Colleen Rainbolt
Greg Davidson
Etan Karni
Lazo Trkulja
March 24, 2005
Tyler Start

2. Mission Specifications
8 Minute Endurance
Vstall ≤ 20 fps
Vloiter ≤ 30 fps
Climb ≥ 20
descent ≤ -5.5
Stylish

3. Style Features Canard pusher configuration Blended wing-body design
Retractable landing gear
LED lighting
Ventral fins
Winglets

4. Vehicle 3-View Length 4.21 ft. Wingspan 4.63 ft. Wing Area 3.58 ft.2
Takeoff Weight
1.95 lbs.
Discuss features:
Unique blended canard design
Retractable landing gear
LED lighting

5. Dimensions Main Wing Canard Vert. Stab. Airfoil USNPS-4 Flat Plate
Sref
3.58 ft2
0.31 ft2
0.63 ft2 AR
6.0
4.0
1.5
Taper Ratio
0.6
0.5
0.4
Sweep
0 deg.
25 deg.
Dihedral
3 deg.
---

6. Constraint Diagram

7. Master Design Code Automates sizing iteration process
Constraint diagram generation
Propeller analysis using Goldstein’s blade-element method
Motor analysis / comparison using Prop ’02 functions and MotoCalc database
Battery capacity computation from mission model
Sizing of Wing, Canard, and Vertical Stabilizer
Weight estimation based on construction techniques and known systems weights; CG computation
Automatic generation of FlatEarth input deck
Single code approach ensures all disciplines “design the same aircraft”
1200+ lines of team code
Also leverages 450+ lines of existing propulsion analysis codes and lines in FlatEarth aeroprediction code

8. Propulsion

9. Selected Propulsion System
Kokam 3 Cell 640mAh Li-Poly Battery Pack
Kokam Super 20 Electronic Speed Controller

10. Selected Propulsion System
Graupner Speed 480 Brushed Motor
0.12 Hp at 11.1 V and 10 Amps
MPJet 4.1:1 Offset Gearbox
APC 11” x 4.7” Slo-Flyer Propeller

11. Graupner Speed 480 Properties

12. Propeller Properties

13. Aerodynamics

14. Selected Airfoil USNPS – 4 Flat lower surface -- easy to manufacture
Thickness suitable for servos and retracts
High Clmax
Low pitching moment
Low Cd

15. Induced Drag Coefficient
Drag Buildup
Parasite Drag
Induced Drag Coefficient
(ref. Raymer)
Total Drag Coefficient

16. Lift Coefficient 3-D Lift Curve Slope 3-D CLmax
Full Aircraft Zero Degree AoA Lift Coefficient
-FlatEarth.m (ref. Roskam)
Taking into account:
Wing/Body interaction
Incidence Angles
Downwash

17. Desired Operating Point
Polars
Desired Operating Point
CLmax

18. Flight Controls and Performance

19. Location of CG and AC CG AC
SM=19.7% (FlatEarth)
Desired ≥ 15%

20. Stabilizer Sizing with X-Plots
Design Point
Static Margin = 19.7%

21. Sizing of Control Surfaces
All surfaces deflect +/- 30°
30% of chord
Elevator
30% of canard b/2
10% of b/2
Rudder
40% of tail chord
20% of chord
Aileron
40% of wing b/2
10% of b/2

22. Trim Diagram
SM=15%

23. Flight Performance - Takeoff
Vtakeoff= 28 ft/s
ttakeoff = 2.7 s
Xtakeoff = 53 ft

24. Flight Performance - Turning

25. Flight Performance Endurance Climb
Need 489 mAh battery for 8 minute endurance
Battery selected provides 640 mAh (best available match to required capacity)
Climb
Motor selected to provide adequate power for design climb angle with selected prop

26. Control Strategy Feedback yaw rate to the rudder
Expected deficiency in lateral-directional stability due to close coupling of vertical stabilizer and CG
Greater potential for aircraft to enter unrecoverable dive if using pitch feedback
Increase the damping of dutch roll mode from present value of to a recommended maximum value of 0.4

27. Lateral-Directional Root Locus
K = 0.95
*Negative Transfer Function

28. Block Diagram

29. Closed-Loop Pulse Response
Rudder deflected 10 deg.
Rudder neutralized

30. Landing Gear, Structures and Weights

31. Landing Gear Layout Nose gear carries 8% of weight; remainder on mains
Tailstrike at 10.0
20.0 tipback angle
Wingtip strike at 15.7° bank
30.0 overturn angle
1.52 ft. track between main gear
20.0
0.5 ft.
2.15 ft.
10.0

32. Foam Panels (nonstructural)
Fuselage Structure
Foam Panels (nonstructural)
Hollow
Balsa Box Structure
3/16” sq.
Balsa Stringers (4)
1/16” thick

33. Balsa Tristock Bracing
Vertical Stabilizer
3/16” x 1/4” Balsa Fin Structure, Solid Rudder
0.97 ft
0.37 ft
0.93 ft
Balsa Tristock Bracing

34. Balsa Leading Edge Spar
Wing Structure
Balsa Leading Edge Spar
Balsa Subspar
Balsa Wing Skin
Blue Foam Core
Balsa Trailing Edge
0.97 ft
0.03 ft
0.017 ft
0.10 ft
Foam Wing Saddle

35. Bending and Torsion Results
Ultimate Root Bending Moment lbf-ft (tensile failure)
Max Root Bending Moment in Turning Flight lbf-ft
Computed Factor of Safety = 3.3
Maximum twist angle = -0.2 (LE down)

36. Weight Distribution

37. Weight and Balance Origin at wing root c/4
Weight (lbs.)
Arm
(ft.)
Moment
(ft.-lbs.)
Airframe
0.856
-0.12
-0.10
Propulsion
0.666
0.12
0.08
Avionics
0.256
-0.98
-0.25
Landing Gear
0.155
-0.77
Miscellaneous
0.063
-0.16
-0.01
TOTAL
1.950
-0.51
Origin at wing root c/4
Nose-up moments are positive

38. V-n Diagram
Ultimate Load Factor
Mission Load Factor

39. Construction and Test Plan

40. Fabrication Plan Parallel construction process
Also bench test propulsion and avionics prior to installation

41. Flight Test Plan Low/Hi-speed taxi tests
Flight 1A – 1x: Unpowered glide test series
Flight 2: 1st Powered Flight (outdoors)
Flight 3: Envelope expansion (outdoors)
Flight 4A – 4x: Final shakedown (indoors / outdoors)
Flight 5: Demonstrate design mission (indoors)

42. Budget and Labor Budget Labor Team: spent $135.40 of $150 permitted
Purdue: $92.88, excluding R/C gear
Remaining purchases are foam and sheet balsa
Labor
Team has worked 1323 hours to-date
Extrapolating for remainder of semester results in $57,900 at $25/hr/person

43. Remaining Challenges Ready to Build Transportation
Compressed construction / testing schedule
Pilot availability
Ready to Build

44. Questions?

45. Backup charts
Propulsion
Structures
Finance

46. Graupner Speed 480 Rated horsepower 0.1182 hp @ take-off
Motor efficiency
71%
Motor constants
Kv = 2450 RPM/V
Kt = In-oz/amp
R = Ohms
Io = 1.09 Amps
Rated number of cells
3 Lithium
Rated Amps
10 Amps
Rated voltage
8.4 V
Weight
0.221 lbs
Price
$25.90 (Hobby Lobby)

47. Selected Gearbox Gear Ratio (available) 4.1:1 Efficiency 87% Price
$13.90 (Hobby Lobby)

48. Selected Propeller Properties
Prop (Calculated)
11 in. x 4.4 in
Prop (Available)
11 in x 4.7 in
RPM
5000 RPM
Weight
0.113 lbs
Chord
0.6 in.
Airfoil of Propeller
Clark-Y
Price
$3.09
Reynolds Number
~100,000

49. Other Propeller Options
Pitch and Diameter
APC Slow-Flyer
10 x 7
10 x 4.7
11 x 6
11 x 7

50. Battery Properties Kokam 3-Cell 640 mAh Continuous Amps 9.6 A
Nominal Output
11.1 V
Weight
0.119 lbs
Price
$31.99

51. Speed Controller Kokam Super 20 Amp Auto low voltage cutoff (lvc)
Continuous Amps Output
20A
Peak output current
200A
Input operating voltage
2.1 to 18V DC
Weight
lbs
Price
$33.99

52. Propulsion Parts List

53. Bending Results Max Allowable Root Bending Moment
 lbf-ft (tensile failure)
Max Allowable Compressive Moment
 lbf-ft
Max Bending Moment in Loiter
 9.18 lbf-ft
Max Bending Moment in Turning Flight
9.73 lbf-ft

54. USNPS-4 Characteristics

55. USNPS-4 Characteristics

56. USNPS-4 Characteristics

57. (assumed based on historical data and absence of naceles)
Parasite Drag Buildup
,where
Fuselage
,where
Form Factor:
Interference Factor:
(assumed based on historical data and absence of naceles)

58. Parasite Drag Buildup Wings/Canards/Winglets Miscellaneous Drag
(1.02 accounts for thickness/curvature)
Form Factor:
Sweep correction:
Interference Factor:
(assumed based for mid-body, filleted wings)
Miscellaneous Drag
Based on historic small propeller aircraft

59. Total Drag Polar Prediction
Induced Drag Coefficient
Total Drag Coefficient

60. Lift Coefficient
Lift Curve Slope {

61. Break Even Point Final Aircraft Price $228.28 Profit Margin 15%
MSRP of R/C Plane
$262.52
Profit Per Aircraft
$34.24
Units to Break Even
1,691

62. Materials Cost

63. Avionics
JR241 Servos for Rudder/Nose Wheel Steering, Elevator, Flaperons (1 ea.)
JR331 Servo for Retracts
Futaba GYA350 Gyro

64. Constraint Equations
Climb Power Loading
Stall Speed

65. Constraint Equations
Climb Power Loading
Stall Speed

66. Constraint Equations
Sustained Turning
Steady Flight