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Team 5. Conceptual Design Review. Robert Aungst Chris Chown Matthew Gray Adrian Mazzarella. Brian Boyer Nick Gohn Charley Hancock Matt Schmitt. Outline of Presentation. Mission Summary Payload Summary Final Concept Sizing Analysis Aerodynamic Analysis Performance Analysis
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Team 5 Conceptual Design Review Robert Aungst Chris Chown Matthew Gray Adrian Mazzarella Brian Boyer Nick Gohn Charley Hancock Matt Schmitt
Outline of Presentation • Mission Summary • Payload Summary • Final Concept • Sizing Analysis • Aerodynamic Analysis • Performance Analysis • Engine / Power Analysis • Structures Analysis • Stability and Controls Analysis
Concept of Operations “Our mission is to provide an innovative advertising medium through the use of an Unmanned Aerial System (UAS)” • Continuous area coverage of South Florida metropolitan areas and beaches for advertising purposes • Advertisements change based on location and circumstance • Targeted advertising for specific areas • e.g. advertising Best Buy near Circuit City locations • Large, fuselage mounted LED screens will deliver adverts • Business will be developed around this new technology
Concept of Operations Operations based at Sebring Regional Airport, serving 3 high population areas Continuous area coverage of city for 18 hrs (6am to 12am) 3 missions total with 6 hour loiter each Seven planes needed for 3 city operations with 1 spare Coverage area map:
Major Design Requirements • Customer Attributes • Advertisement visibility is paramount in order to meet customer’s needs • Must maintain a loiter speed which allows the public to retain the content of advertisements • For a successful venture, these two requirements must be clearly met in order to provide a superior service to the customer • Engineering Requirements • Screen dimensions: 7.42’ x 30’ (each) • Loiter Speed: 68 ktas • Loiter Endurance: 6 hrs
Payload Summary - Screen Two High Intensity LED Screens 7.42 ft X 30 ft Viewable up to 1500 ft 500 lbs installed (each) $120k cost (each) Power Consumption 3.9 kw/5.2 hp, each Driven by DC Generator Daytime Viewable Brightness: 6500 cd/m² Dynamic Display 60 fps video/text Weatherproof
Selected Aircraft Concept – “Walkaround” Diagram High wing configuration Single 755 hp turboprop, propeller T-tail empennage configuration Retractable tricycle landing gear configuration 7.42’ x 30’ advertising screen High aspect ratio, zero sweep wing
Aircraft Sizing Analysis • Sizing Prediction Methods • NASA Langley’s FLOPS • Flight Optimization System • AVID’s ACS • Team Written Matlab Code • Early Weight Predictions • Team written Matlab code • Empty weight - historical database trends • Final Weight Predictions • NASA’s FLOPS Software • Empty weight - FLOPS general aviation equations
Aircraft Sizing Analysis • Fixed Design Parameter Values
Aircraft Sizing Analysis • Tail Sizing Strategy • Historical values for tail volume coefficient • Raymer plus a “fudge” factor • Horizontal Tail Volume Coefficient: 0.975 • Vertical Tail Volume Coefficient: 0.1 • Engine Modeling • FLOPS turboprop model • Inputs • compressor pressure ratio • turbine inlet temperature • design shaft horsepower • design core airflow • propeller efficiency • propeller RPM
Carpet Plots • Carpet Plots Procedures • Design Wing Loading: 12.5 lbs/ft2 • Design Thrust-to-Weight Ratio: 0.24 • Increase and Decrease Wing Loading and Thrust-to-Weight Ratio by factors of approximately 20% and 40% • Determine from sizing code: • Gross Takeoff Weight • Landing Distance • Takeoff Distance
Carpet Plot Design Area W/S = 12.5 T/W = 0.24
Trade Studies • Using carpet plots • Design wing loading selected • Design thrust-to-weight ratio selected • Trade Studies • Gross Weight Variations from: • Payload weight • Cruise distance • Loiter time
Trade Studies - Payload Weights • 1 LED Screen vs. 2 LED Screens • Cruise Distance = 112 nm • 1 LED Screen • Payload Weight: 500 lbs • Gross Takeoff Weight: 3942 lbs • Empty Weight: 2368 lbs • Fuel Weight: 1008 lbs • 2 LED Screen • Payload Weight: 1000 lbs • Gross Takeoff Weight: 5431 lbs • Empty Weight: 2996 lbs • Fuel Weight: 1360 lbs
Trade Studies - Cruise Distance • 1 LED Screen vs. 2 LED Screens • Varying Cruise Distances
Trade Studies - Loiter Length • 1 LED Screen vs. 2 LED Screens • Varying Loiter Lengths
Aircraft Description – 3-view 10 ft 5 ft 78 ft 3 ft 6 ft 13 ft 42 ft
Aircraft Description - Internal Layout 42 ft. Generator RearLanding Gear Nose Landing Gear (beneath engine) Tail Camera Screen Avionics Engine Fuel 13 ft Nose Camera Screen Ballistic Recovery System
Nose Gear: 4 ft. from the nose Center of plane Retracts to the rear 3.25 ft. long strut .1 ft diameter Oleopneumatic shock-strut with drag brace 2 Type VII tires (redundancy) .4 ft width .75 ft radius 100 psi Rated at 174 kts Main Gear: 22 ft. from the nose Edges of the fuselage Retract to the rear 5.75 ft. long struts .14 ft diameter Oleopneumatic shock-struts with drag braces Type VII tires .4 ft width .75 ft radius 225 psi Rated at 217 kts Aircraft Description - Retractable Tricycle Landing Gear
Aircraft Description - Landing Gear Design Considerations • No tail strike on landing (ground clearance > 1.2 ft) • 2 ft ground clearance • Propeller ground clearance (> .84 ft) • 2 ft ground clearance • Tipback prevention (> 15˚) • Angle of 19˚ off vertical from main gear to center of gravity • Overturn prevention (< 63˚) • Overturn angle 45˚ • Optimal weight sharing (8-15% by nose) • Nose gear carries 10.4% • Main gear retraction • Thin fairing opens at top of screen • Screen assembled in modules
Aerodynamic Design • Wing design summary • Wing details • Airfoil selection and performance characteristics • Parasite drag build-up • Aircraft drag polars • Other aerodynamic considerations
Aerodynamic Design – Wing Spanwise Twist Distribution • Wing twist designed: • to achieve a minimum induced drag spanwise lift distribution • to provide desirable stall characteristics • Preliminary twist distribution derived using lifting-line theory
Aerodynamic Design – Wing Spanwise Thickness Distribution • Thickness distribution designed: • to minimize the form drag of the wing • to provide potential weight savings • Preliminary thickness distribution based on current aircraft designs
Aerodynamic Design - Airfoil Selection - Wing • Wing Requirements • Promotes laminar flow • Delays transition to turbulent flow • In order to accomplish this, the NACA 64-912,10,08 airfoil was chosen for the different thicknesses required NACA 64-912 Drag Polar & Lift-curve slope for NACA 64-912
Aerodynamic Design - Airfoil Selection - Tail • Vertical Tail • Requires a symmetric airfoil to prevent side forces • Horizontal Tail • Must allow for stability of aircraft Chose NACA 0012 for both vertical and horizontal tail • By using the same characteristic airfoil for both, it will reduce manufacturing costs • It meets the symmetry requirements • A 12% thickness, this allows structural considerations NACA 0012
Aerodynamic Design – Parasite Drag Build-up • Two methods were used to predict parasite drag: • Component build-up method* • FLOPS (Flight Optimization System) breakdown • Data from both predictions were analyzed and compared, giving a parasite drag prediction *Aircraft Design: A Conceptual Approach; D.P. Raymer; 2006.
Aerodynamic Design – Parasite Drag Build-up • Parasite drag build-up [clean configuration]:
Aerodynamic Design – Parasite Drag Build-up • Parasite drag breakdown [clean configuration]:
Aerodynamic Design – Drag Polars • Aircraft drag polar [clean configuration]:
Aerodynamic Design – Drag Polars • Aircraft drag polar [dirty configuration]:
Aerodynamic Design – Other Considerations • Winglets • Proposed to add winglets to reduce the wing induced drag • Applicable to this aircraft due to the design mission characteristics: • Long endurance • Low design flight speed. • Winglets increase the effective aspect ratio – sizing code uses the effective aspect ratio • No detailed design carried out • Further detailed aerodynamic design would incorporate winglet design • High-lift devices • With an approach speed of 67 keas, it was felt that high-lift devices, at this stage of the design, were not needed
Performance • Specific excess power • Power available and required • Flight envelope • V-n diagram • Performance summary
Performance – Specific Excess Power • Specific excess power, at maximum gross take-off weight:
Performance – Power Available and Power Required • Power available and power required, at maximum gross take-off weight:
Performance – Flight Envelope • Flight envelope, at maximum gross take-off weight:
Performance – V-n Diagram • V-n diagram (maneuver loads), at maximum gross take-off weight:
Performance – Turn Performance • Turn radius, at maximum gross take-off weight:
Performance – Turn Performance • Time to turn 180° at maximum gross take-off weight:
Performance – Performance Summary Operating Speeds *Approach speed based on 1.3*Vs1-g **Note: best range speed is below the stall speed
Performance – Performance Summary Other ***Take-off and landing distances based on standard sea-level conditions, temperature STD +30F ****Service ceiling based on the FAR requirement of a climb rate of 100 fpm for propeller aircraft
Propulsion System – Engine and Propeller • Power: 776 shp (S.L. static) • SFC: .577 lb/hr/hp @ max power • Cost: $100k-$150k • Dry Weight: 355 lbs • Installed Weight: 500 lbs • Prop Shaft Speed: 2000 RPM • Propeller • Hartzell HC-B3TN-5 • Matched to TPE-331 • 3-Blade, Variable Pitch • Constant Speed, Feathering • Steel Hub, Aluminum Blades • Tip Mach: 0.82 • J: 0.90 AF: 99.8 • η: 0.785 Cp: 0.114 • Honeywell TPE-331-5 Turboprop
Power Budget • Power Source • Up to 50 hp extracted from engine • D.C. generator attached to accessory gearbox • Power Requirements • LED Screens • 2 @ 5.2 hp = 10.4 hp • MicroPilot MP-Day/Nightview Cameras • 2 @ 6 watts = 0.02 hp • Avionics Components • Communications (VHF/UHF), Navigation (GPS), Flight Control, Telemetry, Video • Estimated @ 20 kW = 26.8 hp • ~37 hp used, 13 hp reserve available
Structure - Internal Structural Layout Key: Stringer: Rib: Spar: 13 ft 1.88 ft Ribs 42 ft Front Spar 2.5 ft 2.5 ft 1.88 ft 3.13 ft Main Spar Rear Spar Stringers 78 ft 1.25 ft
Structure - Aircraft Material Selection • Skin (Aramid/Epoxy): 49% weight savings, same modulus, 10x the ultimate strength • High strength resists FOD damage • Stringers (Boron/Aluminum): Same weight, but 3x modulus increases fuselage rigidity • Inhibits LED screen damage from fuselage strain • Spars (Boron/Aluminum): Same weight, but 3x modulus increases wing rigidity • Large span would otherwise exhibit wing bending; increases aerodynamic efficiency • Ribs (Carbon/Epoxy): 43% weight savings, 2x stiffer inhibit wing twist • High wing-twist resistance increases aerodynamic efficiency and endurance
Stability and Control- Weight Summary • Aircraft and Component Weights • FLOPS sizing code • FLOPS is widely used for aircraft of this size • The results, overall, agree with earlier sizing studies
Stability and Control – Static Margin • Static Margin • From internal layout and weight summary • Fuel tank located near the c.g. • Very little c.g. travel as fuel is burned • Static margin remains constant throughout mission 42 ft. 9 in 19.95 ft 13 ft Datum
Cost • Aircraft development and maintenance costs estimated from FLOPS cost model • Production includes 7 complete aircraft with 2 spare engines • Payroll assumes 21 person staff, with a rotation of 12 operators • Revenue model based on servicing 3 cities, 18 hours per day, 50 weeks per year