The Black Pearl

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