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

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

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

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

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. ---

Constraint Diagram

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 3700+ lines in FlatEarth aeroprediction code

Propulsion

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

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

Graupner Speed 480 Properties

Propeller Properties

Aerodynamics

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

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

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

Desired Operating Point Polars Desired Operating Point CLmax

Flight Controls and Performance

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

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

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

Trim Diagram SM=15%

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

Flight Performance - Turning

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

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 0.275 to a recommended maximum value of 0.4

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

Block Diagram

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

Landing Gear, Structures and Weights

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

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

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

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

Bending and Torsion Results Ultimate Root Bending Moment 31.83 lbf-ft (tensile failure) Max Root Bending Moment in Turning Flight 9.73 lbf-ft Computed Factor of Safety = 3.3 Maximum twist angle = -0.2 (LE down)

Weight Distribution

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

V-n Diagram Ultimate Load Factor Mission Load Factor

Construction and Test Plan

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

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)

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

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

Questions?

Backup charts Propulsion Structures Finance

Graupner Speed 480 Rated horsepower 0.1182 hp @ take-off Motor efficiency 71% Motor constants Kv = 2450 RPM/V Kt = 0.5520 In-oz/amp R = 0.241 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)

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

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

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

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

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 0.0265 lbs Price $33.99

Propulsion Parts List

Bending Results Max Allowable Root Bending Moment  31.83 lbf-ft (tensile failure) Max Allowable Compressive Moment  88.05 lbf-ft Max Bending Moment in Loiter  9.18 lbf-ft Max Bending Moment in Turning Flight 9.73 lbf-ft

USNPS-4 Characteristics

USNPS-4 Characteristics

USNPS-4 Characteristics

(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)

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

Total Drag Polar Prediction Induced Drag Coefficient Total Drag Coefficient

Lift Coefficient Lift Curve Slope {

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

Materials Cost

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

Constraint Equations Climb Power Loading Stall Speed

Constraint Equations Climb Power Loading Stall Speed

Constraint Equations Sustained Turning Steady Flight