Conceptual Design Review - AAE 451 - Team 5 April 17, 2007 Slide 1 Conceptual Design Review Robert Aungst Chris Chown Matthew Gray Adrian Mazzarella Brian

Conceptual Design Review - AAE 451 - Team 5 April 17, 2007 Slide 1

Conceptual Design Review

Robert AungstChris ChownMatthew GrayAdrian Mazzarella

Brian BoyerNick GohnCharley HancockMatt Schmitt

Team 5


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

• 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

“Our mission is to provide an innovative advertising medium through the use of an

Unmanned Aerial System (UAS)”


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

7.42’ x 30’

advertising

screen

T-tail empennage

configuration

High wing

configuration

High aspect

ratio, zero

sweep wing

Single 755 hp

turboprop, propeller

Retractable

tricycle landing

gear

configuration


Selected Aircraft Concept – Key Figures

Requirement Final Value

Screen Dimensions (each)

7.42’ x 30’

Loiter Velocity 68 kts TAS

Loiter Time 6 hrs

Cruise Range 400 nm

Loiter L/D (clean) 21

Specific Fuel Consumption

0. 55 lb/BHP/hr

Cruise Velocity 165 kts TAS

GTOW 5585 lbs


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



• Fixed Design Parameter Values

Design Parameter FLOPS Input ValueCLmax

1.2

Thickness-to-Chord Ratio .10

Taper Ratio .39

Wing Sweep 0°

Effective Aspect Ratio 16.8

Screen Size/Weight 7.42” x 30” (drove fuselage dimensions input)/1000 lbs

Weight Correction Advanced Composites Assumed

Atmosphere Correction Standard Atmosphere + 30°F



• 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

Cruise Range: 1 LED Screen(Payload = 500lbs)

2 LED Screen(Payload = 1000lbs)

175 N.M. Cruise

GTOW: 4243 lbs.Empty: 2491 lbs.Fuel: 1184 lbs.


150 N.M. Cruise



100 N.M. Cruise




Trade Studies - Loiter Length

• 1 LED Screen vs. 2 LED Screens• Varying Loiter Lengths

Loiter Length: 1 LED Screen(Payload = 500lbs)

2 LED Screen(Payload = 1000lbs)

4 hr. Loiter GTOW: 3336 lbs.Empty: 2124 lbs.Fuel: 650 lbs.





GTOW: 6682 lbs. Empty: 3570 lbs.Fuel: 2029 lbs.


13 ft42 ft

Aircraft Description – 3-view

78 ft

5 ft

6 ft

10 ft

3 ft


Aircraft Description - Internal Layout

Screen

Screen

Engine

Generator

Avionics

Nose Camera

Tail Camera

Ballistic Recovery System

42 ft.

13

ft

Rear Landing Gear

Fuel

Nose Landing Gear

(beneath engine)


Aircraft Description - Retractable Tricycle Landing Gear

• 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 - 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 Design Summary

Parameter Value Units

Wing area 434.51 ft2

Wing span 77.99 ft

Root chord 8.03 ft

Tip chord 3.11 ft

Mean aerodynamic chord 5.93 ft


Aerodynamic Design – Wing Design Summary

Parameter Value Units

Taper ratio 0.39 Non-dimensional

Geometric aspect ratio

14.0 Non-dimensional

Effective aspect ratio (due to winglets)

16.8 Non-dimensional

Quarter chord sweep 0.0 °Leading edge sweep 0.0 °Dihedral 0.0 °


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

Wing Twist Distribution

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

5.00

0.00 0.20 0.40 0.60 0.80 1.00 1.20

Non-dimensional Spanwise Location, eta = 2y/b

Tw

ist

ang

le [

deg

.]


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

Wing Thickness-to-Chord Distribution

0.060

0.070

0.080

0.090

0.100

0.110

0.120

0.130

0.00 0.20 0.40 0.60 0.80 1.00 1.20

Non-dimensional Spanwise Location, eta = 2y/b

t/c


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

Drag Polar & Lift-curve slope for NACA 64-912

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.



Component Form Factor

Reference Reynolds Number

[106]

Skin Friction

Coefficient

Wetted Area

[ft2]

Drag Coefficient

Wing 1.190 4.20 0.0029 747.77

0.0061

Fuselage 1.611 29.76 0.0025 763.98

0.0070

Horizontal Tail

1.184 1.74 0.0040 78.18 0.0009

Vertical Tail 1.184 3.74 0.0041 181.27

0.0021Miscellaneous Drag 0.0048

Protuberance Drag 0.0021

Total Parasite Drag = 0.0231

• Parasite drag build-up [clean configuration]:



• Parasite drag breakdown [clean configuration]:

Profile Drag Breakdown [Clean Configuration]

27%

30%4%

9%

21%

9%

Wing

Fuselage

Horizontal Tail

Vertical Tail

Miscellaneous Drag

Protuberance Drag


Aerodynamic Design – Drag Polars

• Aircraft drag polar [clean configuration]:

Com plete Aircraft Drag Polar [Clean Configuration]

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

-0.80 -0.60 -0.40 -0.20 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60

CL

CD


Aerodynamic Design – Drag Polars

• Aircraft drag polar [dirty configuration]:

Com plete Aircraft Drag Polar [Dirty Configuration]

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

-0.80 -0.60 -0.40 -0.20 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60

CL

CD


Aerodynamic Design – Other ConsiderationsWinglets• 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:

Specific Excess Power - Flight Envelope

0

5000

10000

15000

20000

25000

30000

35000

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Mach Number

Pre

ss

ure

Alt

itu

de

(ft

)

0 ft/min

100 ft/min

500 ft/min

1000 ft/min

1500 ft/min

2000 ft/min

2500 ft/min

3000 ft/min


Performance – Power Available and Power Required

• Power available and power required, at maximum gross take-off weight:

Power Available and Power Required

0

50

100150

200

250

300

350

400450

500

550

600

650

700750

800

850

900

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Mach Number

Po

wer

Ava

ilab

le a

nd

Po

wer

Req

uir

ed

(hp

)

1,000 ft.

10,000 ft.

Power Available

Pavail after extraction


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:

V-n Diagram [Maneuver]

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

0 20 40 60 80 100 120 140 160 180 200 220 240

Veas [kts]

n

@ Maximum Gross Take-off Weight, 5432 lbs


Performance – Turn Performance

• Turn radius, at maximum gross take-off weight:

Turn Performance - Turn Radius

0

200

400

600

800

1000

1200

1400

0 20 40 60 80 100 120 140 160 180 200

Veas [kts]

Tu

rn R

adiu

s [f

t]

Stall Boundary Maximum Load Factor Boundary

Sta

ll B

ound

ary

@ Maximum Gross Take-

off Weight, 5432 lbs


Performance – Turn Performance

• Time to turn 180° at maximum gross take-off weight:

Turn Performance - Time to Turn 180 degrees

0

5

10

15

20

25

0 20 40 60 80 100 120 140 160 180 200

Veas [kts]

Tim

e to

Tu

rn 1

80 d

egre

es [

s]

Stall Boundary Maximum Load Factor Boundary

@ Maximum Gross Take-

off Weight, 5432 lbs

Sta

ll B

ound

ary


Performance – Performance Summary

Stall speed 51 keas

Loiter speed 67 keas

Cruise speed 162 keas

Maximum speed 223 keas

Approach speed* 67 keas

Best range speed** 46 keas

Best endurance speed

61 keas

Operating Speeds

*Approach speed based on 1.3*Vs1-g

**Note: best range speed is below the stall speed


Performance – Performance Summary

Take-off distance***

1910 ft

Landing distance***

3650 ft

Service Ceiling**** 30800 ft

Wing Loading 12.5 lbs/ ft2

Design Point L/D 21.0 Non-dimensional

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

• Honeywell TPE-331-5 Turboprop– 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


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

13 ft

78 ft

42 ft

Rear SparMain Spar

Front SparRibs

Stringers

2.5 ft

2.5 ft

1.88 ft

3.13 ft

1.88 ft

1.25 ft

Key:

Stringer:

Rib:

Spar:


Structure - Aircraft Material Selection

Component Material Modulus (GPa) Ultimate Strength (GPa) Density (g/cm^3)

SkinAramid/Epoxy (Kev 49/Epoxy) 70.00 1.40 1.40

StringersBoron/Aluminum (B/Al 2024) 210.00 1.50 2.65

SparsBoron/Aluminum (B/Al 2024) 210.00 1.50 2.65

RibsCarbon/Epoxy (AS4/3501-6) 140.00 2.10 1.55

ComparisonAluminum (2024) 70.00 0.14 2.70

ComparisonTitanium (Ti-6Al-4V) 110.00 0.92 4.46

•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 SummaryMASS AND BALANCE SUMMARY % TOTAL POUNDS

Wing 17.85 969Horizontal Tail 0.61 33Vertical Tail 1.69 92Fuselage 11.86 644Landing Gear 3.73 202STRUCTURE TOTAL 35.74 1941

Engines 6.35 500Fuel System - Tanks and Plumbing 2.43 132PROPULSION TOTAL 8.78 632

Surface Controls 0.71 38Hydraulics 3.48 189Electrical 2.76 150Avionics 0.92 50Ballistic Recovery System 0.69 150SYSTEMS AND EQUIPMENT TOTAL 10.63 577Weight Empty 55.15 3150

Unusable Fuel 1.21 66Engine Oil 0.16 9Operating Weight 56.54 3225

Advertising Screens 18.41 1000Zero Fuel Weight 74.95 4225

Mission Fuel 25.05 1360Ramp (Gross) Weight 100.00 5585

• 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.

13

ft 19.95 ft 9 in

Location (ft)C.G. 19.95Xn 20.70SM 0.13

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

Startup Costs

Development $2,619,000.00

Production $26,845,000.00

Office Equipment $100,000.00

Payroll $7,680,000.00

Cost of Manufacturing Site $240,000.00

Advertising $2,160,000.00

Subtotal $39,644,000.00

Operating Costs (Yearly)

Fuel $3,359,700.00

Maintenance $9,044,600.00

Payroll $5,260,000.00

Advertising $720,000.00

Hangar Costs $33,800.00

Subtotal $18,418,100.00

Summary

Yearly Revenue $25,130,250.00

Yearly Income $6,712,150.00

Years to Break Even 6


Conclusions – Selected Concept

7.42’ x 30’

advertising

screen

T-tail empennage

configuration

High wing

configuration

High aspect

ratio, zero

sweep wing

Single 755 hp

turboprop, propeller

Retractable

tricycle landing

gear

configuration


Conclusions - Design Compliance

Requirement Final Target Initial

Screen Dimensions (each)

7.42’ x 30’ 7.42’ x 30’ 8’ x 45’

Loiter Velocity 68 kts TAS < 65 kts < 55 kts

Loiter Time 6 hrs > 6 hrs > 8 hrs

Cruise Range 400 nm > 400 nm > 400 nm

Loiter L/D (clean) 21 > 16 > 22

Specific Fuel Consumption

0. 55 lb/BHP/hr

< 0.5 lb/BHP/hr

< 0.5 lb/BHP/hr

Cruise Velocity 165 kts TAS

> 80 kts > 135 kts


Conclusions - Project Feasibility

• While technically feasible, the project has major pitfalls• FAA regulations greatly restrict flight over

populated areas• Business case is overly optimistic of

industry• Price point is very high• Cost model assumes infinite demand• Innovative idea could invigorate industry


Conclusions - Future Work

• Business– Market Research to confirm business

feasbility

• Aerodynamic Analysis– CFD Analysis to confirm FLOPS results

• Structural Analysis– Generation of predicted loads– Finite Element Analysis

• Stability– Lateral Stability Analysis– Aileron and Rudder Sizing– Elevator Sizing


Questions?

Thank you for your time!Comments and Questions?

Documents

Conceptual Design Review - AAE 451 - Team 5 April 17, 2007 Slide 1 Conceptual Design Review Robert Aungst Chris Chown Matthew Gray Adrian Mazzarella Brian