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Systems Design Review Presentation

Joe AppelTodd Beeby

Julie Douglas

Konrad HabinaKatie Irgens

Jon Linsenmann

David LynchDustin Truesdell

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Outline• Mission statement• Design requirements• Concept generation and selected concepts• Technology and effects• Engine sizing and technology• Constraint diagrams• Sizing code• Stability, CoG and Tail Sizing• Summary of aircraft concepts• Next Steps

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Mission Statement• Design an Environmentally Responsible Aircraft (ERA) that

lowers noise, minimizes emissions, and reduces fuel burn

• Utilize new technology to develop a competitive medium-size aircraft that meets the demands of transportation for continental market

• Deliver a business plan focusing on capitalizing on growing markets

• Submit final design to NASA ERA College Student Challenge

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Major Design Requirements

• NASA ERA Goals

Large twin aisle reference configuration = Boeing 777-200LR

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Major Design Requirements

• Market Goals– 200 passengers– Intra - Continental Range

• 3200 Nautical Miles

• Operability– Maintenance– Turnaround time– Production and operating costs

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Design Process

• Concept Generation– Created functional flow block diagram– Brainstormed design features– Assembled morphological matrix– Designed 8 initial concepts– Two rounds of Pugh's method

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Concept Generation & Selection – Initial Concepts

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Selected Concepts: Concept 1

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Concept 1

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Concept 1: Cabin Layout

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Concept 2

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Concept 2

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Concept 2: Cabin Layout

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Technologies

• Concept 1:– “Double bubble” fuselage– C - wing– Aft mounted engines

• Concept 2:– High wing– Under wing engines– High aspect ratio wing

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Technologies

• On both concepts– Laminar flow– Composite Materials

Courtesy NASA

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Technology Effects

• Double Bubble Fuselage– 19% fuel burn reduction, 15 min load/unload time

reduction, pressurization difficulties• C – wing

– 11% reduction in induced drag, increased wing weight

• Aft mounted engines– 16 % fuel burn reduction, 5db noise reduction,

maintenance issues

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Technology Effects

• High Wing– Allows for GTF to be fixed in under wing configuration

• Under Wing Engines– No increase in maintenance time or cost

• High AR Wing– 1% increase in span = 1.7% decrease in induced drag

• Laminar Flow– 25% laminar flow on wing = 25% reduction in parasite

drag, no leading edge devices limits slow speed ability

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Technology Effects

• Composite Materials– Fiber Laminate Core(FLC) reduces over 40%

directional strength, 15% lower density then Al– Alcoa Wing Box, 20% wing weight reduction

Photos courtesy of ALCOA

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Engine Selection• The Geared Turbo Fan (GTF)• Pros - Fuel economy-up to 15% savings• Noise-max of10dB reduction• Emissions –surpass CAEP/6 by 50% for NOx• Cons - Maintenance costs for gearbox

http://www.aric.or.kr/trend/history/images/propellant/pw_geared_turbofan.jpg

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Engine Sizing• Modeling the baseline engine to the GEnx-1B64 • Modeled engine features: Weight=11,900 lbs; T:W=4.951;

BPR=10; Pressure ratio 20:1 • Genx-1B64 features: Weight=12822 lbs ; T:W=5.21; BPR=19/2;

Pressure ratio 23:1 Altitude (ft) Thrust (lbf) TSFC (lb/hr/lbf)

0 61800 0.262

5000 59500 0.263

10000 50800 0.268

15000 42900 0.273

20000 35900 0.28

25000 29700 0.287

30000 24300 0.294

35000 19700 0.302

40000 15500 0.303

45000 12200 0.303Courtesy GE Aircraft Engines

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Engine Technology Effects

• Cheverons-Improved exhaust and bypass air mixing reducing engine exhaust noise by 3 dB

• Soft Vanes-Reduce fan noise by 1-2 dB by reducing unsteady pressure response on stator surface.

http://memagazine.asme.org/articles/2006/november/Put_Nozzle.cfm

Assessment of soft vane and metal foam engine noise reduction concepts-NASA Glenn

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Major Performance Constraints

• Top of Climb:– Alt = 42,000 ft, Mach = 0.75

• 2-G Maneuver:– Alt = 10,000 ft, V = 250 Kts,

• Landing Braking Ground Roll @ High-Hot Cond. :– Length = 4000 ft, (Alt = 5000 ft, T = +15 F)

• Takeoff Accel. Ground Roll @ High-Hot Cond. :– Length = 2000 ft

• Second Segment Climb @ High-Hot Cond.:– 1 engine out, FAA min. climb gradient (2.4%)

Input L/D We/W0 α SFCc SFCl (CL)max CD0 Vst Vt/o Vappr

Value 19 0.48 -1.18 0.5 0.4 2.26 0.015 120 150 165Unit -- -- lbf/ft lb/(lbf*h) lb/(lbf*h) -- -- knots knots knots

Basic Assumptions

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• Concept 1 – Double Bubble

• Concept 2 – High Wing

Input L/D We/W0 α SFCc SFCl (CL)max CD0 Vst Vt/o Vappr

Value 19 0.54 -1.18 0.5 0.4 2.26 0.015 120 150 165Unit -- -- lbf/ft lb/(lbf*h) lb/(lbf*h) -- -- knots knots knots

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Constraint Diagram: Concept 1

50 60 70 80 90 100 110 120 130 140 1500

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8Airfinity - Constraint Diagram Concept 1

W0/S

T sl/W

0

Top of climb @ 42,000 ft M = 0.75

2g maneuver @ 10,000 ft, 250 kts

Takeoff ground roll 4000 ft @ high-hot conditions (5000 ft, +15 F)Landing braking ground roll 2000 ft @ high-hot

Second segment climb high-hotTsl/W0 = 0.29

(lbf/lb)

W0/S = 103 (lbs/ft2)

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Constraint Diagram: Concept 2

Tsl/W0 = 0.26 (lbf/lb)

W0/S = 84 (lb/ft2)

50 60 70 80 90 100 110 120 130 140 150

0

0.1

0.2

0.3

0.4

0.5

0.6

Airfinity - Constraint Diagram Concept 2

W0/S

T sl/W

0

Top of climb @ 42,000 ft M = 0.72

2g maneuver @ 10,000 ft, 250 kts

Takeoff ground roll 4000 ft @ high-hot conditions (5000 ft, +15 F)Landing braking ground roll 2000 ft @ high-hot

Second segment climb high-hot

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Trade Studies

• Aspect Ratio– Varied aspect ratio between 9 & 20

• Mach Number– Target performance specifications yielded a mach

number of 0.75• Sweep

– Researched the effects of sweep between 0 ° & 35° on both concepts and chose appropriate sweep angles

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Aircraft Design Mission

01

2

4 5

76

4’ 5’

8 9Taxi & takeoff

Clim

b

Cruise ClimbNo rangedescent

Loiter (30 min)

Land

Clim

b

No rangedescent

Land

Attempt to Land

Loiter (30 min)

6800 ft Range: 3200 nmi 4950 ft Fuel Reserves

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32000 ft

Code Status

Current StatusValidated Code for Boeing 757-200 and 767-200ERSplit up sizing code into weight and drag componentsLocation of center of gravity for Hybrid Concepts

Validation using similar a/c: Boeing 757-200TOGW = 255000 lb, OEW = 127000 lb, Wfuel = 74510 lb

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Initial SizingParameter Value Units Error

W0 design 259240 lb 1%

We design 132260 lb -2%

Wf design 81580 lb 9%

Component WeightsParameter Value Units Error

W0 design 260310 lb 2%

We design 122980 lb -3%

Wf design 79330 lb 6%

Input L/D We/W0 α SFCc SFCl (CL)max CD0 Vst Vt/o Vappr

Value 19 0.48 -1.18 0.5 0.4 2.26 0.015 120 150 165Unit -- -- lbf/ft lb/(lbf*h) lb/(lbf*h) -- -- knots knots knots

Basic Assumptions

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• Concept 1 – Double Bubble

• Concept 2 – High Wing

Input L/D We/W0 α SFCc SFCl (CL)max CD0 Vst Vt/o Vappr

Value 19 0.54 -1.18 0.5 0.4 2.26 0.015 120 150 165Unit -- -- lbf/ft lb/(lbf*h) lb/(lbf*h) -- -- knots knots knots

Sizing Approach

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• Empty Weight– Statistical equations for components from Raymer Text– Weights added to Payload & Fuel to estimate TOGW– If fuel weight isn’t sufficient, weights adjusted (iteration)

• Fuel Weight– Segment fuel fractions using Range and Endurance eqns

• Drag– Component drag build-up

• Parasite, for each exposed aircraft component• Induced, for wing and tail surfaces• Wave, neglected for cruse Mach ~ 0.75

Input W0/S TSL/W0 AR Λ t/c (CL)max

Value 103 0.29 10 25 0.1 2.26Unit lb/ft2 -- -- deg -- --

Concept Descriptions

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• Concept 1 – Double Bubble

• Concept 2 – High Wing

Input W0/S TSL/W0 AR Λ t/c (CL)max

Value 84 0.26 18 6 0.1 2.26Unit lb/ft2 -- -- deg -- --

Component Weight Breakdown

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Double Bubble High Wing

Fuselage: 20585 lbsWing: 22470 lbs

Engine: 21600 lbsHoriz Tail: 9329 lbsVert Tail: 2402 lbs

Furnishings: 21717 lbsNacelle: 5262 lbs

Landing Gear: 4862 lbsAvionics: 1840 lbs

Electrical: 1041 lbsAPU: 616 lbs

Instruments: 504 lbsHydraulics: 326 lbs

Engine Ctrls: 88 lbs

Fuselage: 21452 lbsWing: 30291 lbs

Engine: 21600 lbsHoriz Tail: 8845 lbsVert Tail: 2918 lbs

Furnishings: 21918 lbsNacelle: 5262 lbs

Landing Gear: 4751 lbsAvionics: 1840 lbs

Electrical: 1041 lbsAPU: 616 lbs

Instruments: 580 lbsHydraulics: 424 lbs

Engine Ctrls: 88 lbs

Sizing Output

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Double Bubble High Wing

Empty Wt Fraction: 0.48TOGW: 264400 lbsOEW: 128000 lbsEmpty Wt: 126000 lbsFuel Wt: 77500 lbsPayload Wt: 59000 lbsCrew Wt: 1800 lbs

Empty Wt Fraction: 0.53TOGW: 257400 lbsOEW: 138000 lbsEmpty Wt: 136200 lbsFuel Wt: 60000 lbsPayload Wt: 60000 lbsCrew Wt: 1800 lbs

Center of Gravity

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• Concept 1 – Double Bubble Static Margin = -20

Datum c.g. 73’

65’

69’

122’

125’

130’

a.c. 93’

Center of Gravity

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• Concept 2 – High Wing Static Margin = -18

Datum c.g. @ 70’

56’

69’

75’

145’

150’

a.c. @ 88’

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Tail Sizing

• Relate wing aspects to tail– Wing yaw moments countered by wing span– Pitching moments counted by wing mean chord– Correlate using volume coefficients

• Equations 6.28 & 6.29 from Raymer

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Concept 1: Exterior

130’

20’

160’

15.6’

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Concept 1: Interior

• Cabin height = 7ft 2in

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Concept 1: LOPA

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Concept 2: Exterior

231’

150’

17.8’

17.5’

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Concept 2: Interior

• Cabin height = 7ft 2in

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Concept 2: LOPA

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Compliance Matrix

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Next Steps

• Drag component build up• Carpet plots and more in-depth trade studies• C.G. travel diagram• Additional technology integration• Improve engine model accuracy

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On a scale of one to ten,

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Concept Generation & Selection

• House of Quality

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AppendixMorphological Matrix

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AppendixPugh’s Method