The Black PearlThe Black Pearl
AME 441: Senior Design AME 441: Senior Design Group 1Group 1
RRyan yan CCobbobbJJacob acob CCongeronger
CChristopher hristopher CCottinghamottinghamTTravis ravis DDouvilleouvilleJJosh osh JJohnsonohnsonAAdam dam LLoverrooverroTTony ony MMaloneyaloney
Design ProposalDesign Proposal Design DriversDesign Drivers
Maximum Level SpeedMaximum Level Speed Maximum Climb RateMaximum Climb Rate
ObjectivesObjectives Increase Available Increase Available
PowerPower Decrease DragDecrease Drag Decrease WeightDecrease Weight
Low-Drag Flying Low-Drag Flying WingWing With Drag-reducing With Drag-reducing
wingletswinglets
Initial Design Initial Design ConsiderationsConsiderations
StabilityStability Wing SweepWing Sweep Wing TwistWing Twist Reflexed Camber Line Reflexed Camber Line
AirfoilsAirfoils Proper Payload Proper Payload
ArrangementArrangement WingletsWinglets
FabricationFabrication No fuselage or tailNo fuselage or tail Fewer control Fewer control
surfacessurfaces
Takeoff & LandingTakeoff & Landing Takeoff SledTakeoff Sled Landing SkidsLanding Skids
Payload Payload ArrangementArrangement Increased Root Increased Root
ThicknessThickness Internal Storage Internal Storage ~ 70 in~ 70 in3 3 interiorinterior
Comparison AircraftComparison Aircraft
The The Black Black PearlPearl
Zagi Zagi XTXT
SurikSurikatyaty
XE2XE2--
400400
Paoli Paoli Flying Flying Wing Wing
(unpower(unpowered)ed)
ThundThunder er
Tiger Tiger
TOW TOW (lbs)(lbs)
4.2 4.2 2.122.1255
3.53.5 1.51.5 2.052.05 4.8 4.8
Wing Wing Span Span (ft)(ft)
5.8 5.8 4 4 6.426.42 44 8.78.7 5.025.02
Wing Wing Area Area (in(in22))
707707 425 425 751 751 502 502 966966 400 400
Wing Wing LoadinLoadin
g g (oz/in(oz/in22))
0.0950.095 0.080.08 0.750.75 0.00.055
0.0340.034 0.1920.192
Fuselage DesignFuselage Design
No Actual FuselageNo Actual Fuselage Wing root thickened to Wing root thickened to
accommodate payloadaccommodate payload Optimized airfoil fuselage shapeOptimized airfoil fuselage shape
Wing BubbleWing Bubble
Stability DesignStability Design
Payload Payload arrangementarrangement C.G. Forward of C.G. Forward of
A.C.A.C. Positive Static Positive Static Margin (SM = 0.11)Margin (SM = 0.11)
Wing Sweep: 20Wing Sweep: 20oo
Aerodynamic TwistAerodynamic Twist Reflexed Camber Reflexed Camber
Line AirfoilLine Airfoil Low (or positive) Low (or positive)
moment coefficientmoment coefficient
Aerodynamic Wing TwistAerodynamic Wing Twist
Stability DesignStability Design
Winglets Winglets Enhance directional Enhance directional
stabilitystability Wing alone is Wing alone is
directionally stabledirectionally stable
Reflexed trim Reflexed trim positionposition
Control SurfacesControl Surfaces Preliminary:Preliminary:
SSff/S/Sww = 0.2958 = 0.2958 SSaa/S/Sww = 0.1225 = 0.1225 Plane FlapsPlane Flaps CCL= 1.5 with flaps = 1.5 with flaps CCL= 1.0 without flaps= 1.0 without flaps
Final:Final: Flaps UnnecessaryFlaps Unnecessary Flaps & Ailerons Flaps & Ailerons
LinkedLinked Elevons enhance Elevons enhance
control authoritycontrol authority
Engine PerformanceEngine Performance
Astro 15 Static Astro 15 Static ThrustThrust Predicted Thrust: 6.0 Predicted Thrust: 6.0
lblbff
Actual Thrust: 3.15 lbActual Thrust: 3.15 lbff
T/W Ratio T/W Ratio Predicted: 0.96Predicted: 0.96 Actual: 0.75Actual: 0.75
12 x 6 Pusher 12 x 6 Pusher PropellerPropeller
12 Cell Battery12 Cell Batteryhttp://www.flyhobbies.com/astroflightcobalt15geared.htm
Battery ComplicationsBattery Complications 12 Ni-Cad Cells 12 Ni-Cad Cells
spliced to custom spliced to custom fit forward in fit forward in bubblebubble
Learning CurveLearning Curve Discharging, Discharging,
charging problemscharging problems Soldering Soldering
ConnectionsConnections
Takeoff SledTakeoff Sled
Steerable sled for Steerable sled for 211 ft. takeoff roll211 ft. takeoff roll
Carbon-reinforced Carbon-reinforced Ply BasePly Base
Dowels through wingDowels through wing
Sled ComplicationsSled Complications Field bumps/wind Field bumps/wind
gusts change effective gusts change effective angle of attack on angle of attack on each half-span. each half-span.
Asymmetric lift-off Asymmetric lift-off causes binding in causes binding in dowel slots.dowel slots.
Mechanical forces Mechanical forces magnify friction on magnify friction on dowels.dowels.
Solution: Hand Solution: Hand LaunchLaunch
StructureStructure
Two main Two main basswood spars basswood spars
Carbon fiber carry-Carbon fiber carry-through sparthrough spar
Root section 3.25” Root section 3.25” x 14” cutout for x 14” cutout for propeller propeller
Thin Balsa wood Thin Balsa wood skin skin
Landing SkidsLanding Skids Two plastic skids Two plastic skids
arranged symmetricallyarranged symmetrically Protected propeller Protected propeller Absorbed landing impactAbsorbed landing impact
Motivation for Design
Propellers courtesy of H2
On-board GPS DataOn-board GPS Data
ConclusionsConclusions
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
Winglet Area (in2) 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
QuestionsQuestions