1. AME 441: Conceptual Design Presentation
B-19
Group 5: Andrea Doyle, Tim Kacmar, Ryan Kirker, Meghan
Perry-Eaton, Denis Sullivan, Mike Trela, Thomas Zieg
February 5, 2004

2. Overview Introduction Main Wing Selection Engine Selection
Takeoff and Landing Distances
Passive Lift Enhancement
Static Stability
Conclusions

3. Introduction Design Drivers Allowable Parameters
Maximum Level Speed at Constant Altitude
Maximum Climb Rate
Allowable Parameters
Total Planform Area between 400 and 800 in2
Power Plant Consisting of an Electric Motor
Internal Cargo Bay of Specified Dimensions
Sport Propeller of Specific Pitch and Diameter
Digital Radio Control System (7 Channels)

4. Why a Flying Wing? Advantages Minimum Drag High Speed
Absence of Horizontal Tail Maximizes Climb Rate Given AC and CG locations
Maximizing Excess Power

5. Weight Breakdown

6. Wing Loading
Design Drivers:
Max Level Cruise  High Wing Loading
Max Rate of Climb  Low Wing Loading
Large aircraft are not a good comparison.
R/C Model Aircraft Wing Loading
Professional Kit Models: 12 oz/ft2.
Conceptual Design: 27 oz/ft2.
Maximize Available Power, Decrease Drag

7. Overall Wing Design
Taper Ratio, 0.4 – Like Elliptical Planform
Wing Sweep, 20% – Historical Data
Winglets – Decrease Drag, Stability
Dihedral, none
Winglets & Wing Sweep are effective Dihedral
Twist takes away from effective Dihedral

8. Wing Airfoil Section: EH 3.0/12.0
Low Moment about A.C.
-0.002
Thick Section
Structure
Stability
Designed for Flying Wing model Aircrafts

9. Wing Specifics
Flaps for increase lift at take off and acceleration to cruise.
Dimensions
Wing Area, 600 sq. in.
Compromise between low drag and low CL.
Wing Span, 5.4 ft
A = 7.1, 8.1 with winglets
Root Chord, 1.09 ft & Tip Chord .44 ft
cruise, .225

10. Estimated Cruise Velocity Importance
Velocity estimation greatly effects the design of the wing.

11. Estimated Velocity Theoretical Estimate: 100 ft/s
Based on a propeller efficiency ranging from .4 to .6
Conservative Estimate: 80 ft/s
Battery will not be fully charged and other losses will occur.

12. Wing Twist & Angle of Attack
Twist: For Stability & Control of Aircraft
Minimize A.C.
Low Stability Factor, 8%
Longer Wing Span
Good Weight Estimate
Calculated -4° of Twist from Root to Chord
Root Chord, α = 4 °
Tip Chord, α = 0 °
Mean Aerodynamic Chord, α = 2.5°
.817 ft long at 1 ft from the root chord.

13. Propulsion System Astro 15 Motor 12” X 8” Pitch Propeller
9.78 lbs. Static Thrust
2.16 lbs. Cruise Thrust (2 lbs. of Drag at Cruise)

14. Take-Off and Landing Analysis
CDO= 0.015
Aspect Ratio=7.15
CLG=1
Take-off Weight= 8lb
=0.1, wet grass
5 foot obstacle
Wing Loading= lb/ft2
VTD= ft/sec
Landing Weight= 7lb
Dropped landing gears
=0.3, wet grass, large surface area interaction with ground

15. Lift Enhancement Airfoil Data EH3.0-12.0 Cl max = 1.0
αs 2-D no flaps = 10 degrees
CLmax no flaps = 0.90
αs 3-D no flaps = degrees
Flap Information
Plane
δf = 30 degrees
Sf/Sw = 0.20
cf/cw = 0.25
3-D with flaps
ΔCLmax =
CLmax =
αs 3-D flapped = degrees
ΔCD0 =

16. Stability

17. Conclusions Flying Wing Configuration Wing Dimensions
Estimated 8 lb Takeoff Weight
Wing Dimensions
Area: 597 in2
Span: 4.7 ft
Root Chord: 1.08 in Tip Chord: .44 in
Wing Twist: 5°
EH Airfoil
Cl max-1.0
3% Camber
12 % Thickness
Wing Loading
27 oz/ft2

18. Power Plant Takeoff and Landing Flap Information Cruise Speed
Astro Cobalt 15 Electric Motor
-Shaft Output Power: 268 W
-12 Cell Pack
-2.38:1 Gear Ratio
-12x8 Propeller
Takeoff and Landing
Takeoff Speed: ft/s
Takeoff Distance: ft
Landing Distance: ft
Flap Information
Plane
Δf = 30 degrees
Sf/Sw = 0.20
cf/cw = 0.25
Cruise Speed
80 ft/s

19. Questions??