Transcript Document 7251541

The Black Pearl
AME 441: Senior Design
Group 1
Ryan Cobb
Jacob Conger
Christopher Cottingham
Travis Douville
Josh Johnson
Adam Loverro
Tony Maloney
Design Proposal
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Design Drivers
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Objectives
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Maximum Level Speed
Maximum Climb Rate
Increase Available Power
Decrease Drag
Decrease Weight
Low-Drag Flying Wing
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With Drag-reducing
winglets
Initial Design Considerations
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Stability
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Wing Sweep
Wing Twist
Reflexed Camber Line Airfoils
Proper Payload Arrangement
Winglets
Fabrication
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No fuselage or tail
Fewer control surfaces
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Takeoff & Landing
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Takeoff Sled
Landing Skids
Payload Arrangement
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Increased Root Thickness
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Internal Storage
~ 70 in3 interior
Comparison Aircraft
TOW
(lbs)
Wing
Span (ft)
Wing
Area (in2)
Wing
Loading
(oz/in2)
The
Black
Pearl
4.2
Zagi
XT
Surikaty XE2400
Paoli Flying Thunder
Wing
Tiger
(unpowered)
2.05
4.8
2.125
3.5
1.5
5.8
4
6.42
4
8.7
5.02
707
425
751
502
966
400
0.095
0.08
0.75
0.05
0.034
0.192
Fuselage Design
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No Actual Fuselage
Wing root thickened to accommodate payload
Optimized airfoil fuselage shape
Wing Bubble
Stability Design
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Payload arrangement
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C.G. Forward of A.C.
Positive Static Margin
(SM = 0.11)
Wing Sweep: 20o
Aerodynamic Twist
Reflexed Camber Line
Airfoil
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Low (or positive) moment
coefficient
Aerodynamic Wing Twist
Stability Design
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Winglets
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Enhance directional
stability
Wing alone is directionally
stable
Reflexed trim position
Control Surfaces
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Preliminary:
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Sf/Sw = 0.2958
Sa/Sw = 0.1225
Plane Flaps
CL= 1.5 with flaps
CL= 1.0 without flaps
Final:
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Flaps Unnecessary
Flaps & Ailerons Linked
Elevons enhance control
authority
Engine Performance
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Astro 15 Static Thrust
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T/W Ratio
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Predicted Thrust: 6.0 lbf
Actual Thrust: 3.15 lbf
Predicted: 0.96
Actual: 0.75
12 x 6 Pusher Propeller
12 Cell Battery
http://www.flyhobbies.com/astroflightcobalt15geared.htm
Battery Complications
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12 Ni-Cad Cells spliced
to custom fit forward in
bubble
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Learning Curve
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Discharging, charging
problems
Soldering Connections
Takeoff Sled
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Steerable sled for 211 ft.
takeoff roll
Carbon-reinforced Ply
Base
Dowels through wing
Sled Complications
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Field bumps/wind gusts
change effective angle of
attack on each half-span.
Asymmetric lift-off
causes binding in dowel
slots.
Mechanical forces
magnify friction on
dowels.
Solution: Hand Launch
Structure
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Two main basswood
spars
Carbon fiber carrythrough spar
Root section 3.25” x 14”
cutout for propeller
Thin Balsa wood skin
Landing Skids
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Two plastic skids
arranged symmetrically
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Motivation for Design
Protected propeller
Absorbed landing impact
Propellers courtesy of H2
On-board GPS Data
Conclusions
Conceptual
Final
% change
Max Velocity (fps)
98
77
-21.43
Climb Rate (fps)
10
9.5
-5.00
Takeoff Weight (lb)
6.26
4.2
-32.91
Thrust-to-weight
0.96
0.75
-21.88
Wing Loading (oz/in2)
0.125
0.095
-24.00
44
23.625
-46.31
Bubble Volume (in3)
70
70
0
Span (ft)
5.8
5.8
0
Aspect Ratio
6
6
0
Elevon Area (in2)
21
73.8
251.4
Winglet Area
(in2)
Questions