System Definition Review

• XG International

presented by:

Gihun Bae - Joe Blake - Jung Hoon Choi - Jack Geerer - Jean Gong - Daniel Kim - Mike McCarthy - Nick Oschman - Bryce Petersen - Lawrence Raoux - Hwan Song

Outline of ContentsI. Mission StatementII. Market / Customer VerificationIII. CompetitorsIV. Concept of OperationsV. System Design RequirementsVI. Advanced TechnologiesVII. Sizing CodeVIII.Summary / Next Steps

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Mission Statement

Develop an environmentally-sensitive aircraft which will provide our customers with a 21st-century transportation system that combines speed, comfort, and convenience while meeting NASA’s N+2 criteria.

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Design Requirements

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• Noise (dB)– 42 dB decrease in noise

• NOx Emissions– 75% reduction in emissions

• Aircraft Fuel Burn– 40% lower TSFC

• Airport Field Length– 50% shorter distance to

takeoff

**Values for NASA N+2 protocol are found in the Opportunity Statement**

NASA ‘s Subsonic Fixed Wing Project Requirements.

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Aircraft Concept Selection

1. Six Initial Concepts and a Datum2. Pugh’s Method3. Two Result Concepts

Concept Sketches

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Pugh’s Method

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•Started off by choosing criteria using original QFD:– Fuel Efficiency, Airport Flexibility, Noise, Speed, Range, Attractiveness, Green

Image, Personal Space, Passenger Capacity, Smooth Ride (i.e. Overall Vibration)

• Gathered concepts and chose a datum concept, the Gulfstream G250, then formed a matrix comparing everyone’s concepts with the datum concept.

• Ran with +’s, left out –’s and reiterated a couple of times; feasibility a key issue here.

• Took winning ideas, and either added or replaced them on datum concept.

• Produced two, ranked “Winning Concepts”

Pugh’s Method

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Concept Canard/Solar panels 3 engines Dihedral Blended Wing

BodyWinglets,

T-tail,TurbojetsDassault Falcon

2000 EX

Fuel Efficiency = + + + - =

Speed = = = = + =

Quiet = = = + - =

Range - + + + - =

Airport Flexibility - = = - = =

Attractive + = = - = =

Green Image + + = + = =

Personal Space = = = = = +

Smooth Ride + = = - = =

Standing Freedom = = = = = +

Concept Design 1

Turbofan

Solar film

Winglet

Duct

Turboprop

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Concept 1 Cont’d

• 3 Engines -1 Turbofan, 2 Turboprop

• Conventional Tail• Swept back + winglets• Battery powered avionics• Integrated all-weather solar films• NOX-reducing Catalytic Reduction “Green Image”• Active Vibration Control System• Closeable duct – reduce unnecessary drag from resting engine during cruise

Pros• Less expensive development costs• Location of engines doesn’t create

moment about c.g.

Cons• Heavier• Shorter range• Longer take-off Distance• Slower 10

Concept Design 2

Duct

T-TailSolar film

Turbofan

UDF

Canard

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Concept 2 Cont’d

• 2 Vertically oriented engines -1 UDF, 1 Turbofan

• T-tail• Canard

- reduce drag, wing size- create moment about c.g.

• Battery powered avionics• Integrated all-weather solar films• NOX-reducing Catalytic Reduction “Green Image”• Active Vibration Control System• Closeable duct

Pros• Lighter• Faster

Cons• Louder• Harder to control• Higher development costs 12

Closeable Duct

Diverted Airflow diagram Passing Flow diagram

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Advanced Technology

• Engine-Isolated Internal Power System– Solar Film– Lithium-ion Batteries

• Active Vibration Control System• Selective Catalytic

Reduction• Un-ducted Fan

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Advanced Technology Cont’d

• Internal Power : Lithium-Ion Batteries– Replace one APU as power generator for avionics, air-

conditioning, pressurization, lighting, electronics– Equivalent APU weight will provide 5kWh of power – Can be charged directly by solar film or ground power

source– Backup APU used to start engines, for nighttime

operation, as failsafe

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Advanced Technology – Solar Film• Copper Indium Gallium Selenide thin film

– Demonstrated at 19% efficiency– Can be mounted on plastic, glass,

or metal substrate– All-weather application

• Typical performance: >10 W/ft2

• 7.5 hour optimal day-time operation

• Added Weight: 200 lb– Negligible effect on c.g.

http://www.ascentsolar.com/site/epage/87631_870.htm

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Advanced TechnologyActive Vibration Control

• Generates destructive interference– Significantly dampens vibration and noise

throughout cabin– Lightweight

• 10:1 mechanical advantage

– Tunable response• Reduce overall vibration

or eliminate completely in specific section of the aircraft

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Advanced TechnologySelective Catalytic Reduction

• Simple chemical process to remove NOX from exhaust gases

• Primary reaction:NO + NO2 + 2NH3 → 2N2 + 3H2O

• Pertinent issues:– Catalyst delivery/storage– Removing excess from mix– Optimal temperature range

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Advanced TechnologyVortex Generators

• Small vanes or bumps that create turbulence in flow over the wing.

• Reduces pressure drag by delaying flow separation. Also increases the maximum takeoff weight.

• Implementation Prosa) Extremely Light

• Implementation Consa) Difficult to manufacture – increase in

costb) Placement limited – possibly affect

location of solar films

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Major Performance Constraint

• Change from the last constraint diagram– Aspect Ratio– Mach Number– Altitude

o Service Ceiling Height

• Major Constraints– Landing ground roll – Take-off ground roll (for smaller airport compatibility)

Basic Assumptions

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Concept 1 Concept 2

CLmax 1.5 1.5

L/D 2.75 2.83

We/WO 0.743 0.738

SFCcruise 0.5 /hr 0.5 /hr

SFCloiter 0.4 /hr 0.4 /hr

e 0.8 0.8

Vcruise 460 kts 480 kts

Vstall 330 kts 330 kts

Vtake-off 380 kts 450 kts

Vapproach 380 kts 380 kts

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Constraint DiagramConcept 1 Concept 2

50 60 70 80 90 100 110 120 130 140 150

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

1.2

Top of climb (1g steady, level flight, M = 0.80 @ h=45K, ser-vice ceiling)

Subsonic 2g manuever, 250kts @ h =10K

Takeoff ground roll 4000 ft @ h = 5K, +15° hot day

Landing ground roll 2500 ft @ h = 5K, +15° hot day

Second segment climb gradient above h = 5K, +15° hot day

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

0.8

0.9

1

Top of climb (1g steady, level flight, M = 0.80 @ h=45K, ser-vice ceiling)

Subsonic 2g manuever, 250kts @ h =10K

Takeoff ground roll 4000 ft @ h = 5K, +15° hot day

Landing ground roll 2500 ft @ h = 5K, +15° hot day

Second segment climb gradient above h = 5K, +15° hot day

TSL/WO = 0.36 WO/S = 92.6 lb/ft2 TSL/WO = 0.35 WO/S = 88.3 lb/ft2

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Design Mission

Weight Fraction Values State

W1/W0 0.97 Take-Off

W2/W1 0.985 Climb

W3/W2 0.791 Cruise

W4/W3 0.988 Land

W5/W4 0.97 Missed Approach

W6/W5 0.791 Climb

W7/W6 0.979 Divert

W8/W7 0.993 Hold

W9/W8 0.995 Land

W9/W0 0.567 Combined Fraction

Wf/W0 0.459 Fuel Fraction

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Sizing Code• Used Excel Spreadsheet• 6 Different Sections

a) Maini. Fuselageii. Wingiii. Engine

b) Geometryc) Constraint Diagramd) Weighte) Airfoilf) Mission Detail

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ValidationBench Mark : Bombardier Challenger 300

Bombardier Challenger 300 Specification (XG Endeavour)• Range : 3560 nmi (3700 nmi)• Passenger number: 9 (9)• Crew Number : 2 (2)• Cruise Mach Number : 0.8 (0.8)• Service Ceiling : 45000 ft (45000 ft)

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Validation Cont’d

Features that affect the weight based on the sizing code • High Correlation

a) Specific Fuel Consumptionb) Ultimate Load Factor

• Low Correlationa) Aspect Ratiob) Area of the wingsc) Others

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Validation Cont’d

• Weights based on the sizing codea) Empty Weight = 17500lbb) Fuel Weight = 14000lbc) Total Weight = 34400lb

• Actual Weights of Bombardier Challenger 300a) Empty Weight = 18500b b) Fuel Weight = 14100lbc) Total Weight = 35400lb

• Fudge Factor

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Basic AssumptionConcept 1 Concept 2

CLmax 1.5 1.5

L/D 2.75 2.83

We/WO 0.743 0.738

SFCcruise 0.5 /hr 0.5 /hr

SFCloiter 0.4 /hr 0.4 /hr

e 0.8 0.8

Vcruise 460 kts 480 kts

Vstall 330 kts 330 kts

Vtake-off 380 kts 450 kts

Vapproach 380 kts 380 kts

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Current Approach• Current Status

– Able to predict the weight based on 100+ inputs– Empty Weight based on the 22 features of aircraft– Empty Weight fraction based on the equation from Raymer’s– Fuel Weight fraction based on the weight fractions

• Future Work– Drag calculation based on the altitude – Noise calculation

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Current Description

CONCEPT 1 CONCEPT 2

Wo /S 88.35lb/ft2 82.65lb/ft2

TSL/Wo 0.354 0.337

AR 7.8 9

Sweep Angle 35o 35o

t/c 0.5 0.5

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Weight EstimationCONCEPT 1 CONCEPT 2

Wempty 16,700 lb 1,5100 lb

Wfuel 1,4800 lb 1,5000 lb

Wcrew 480 lb 480 lb

Wpayload 2,160 lb 2,160 lb

WO 34,100 lb 32,700 lb

Engine Modeling

• Design concepts require two types of engines to be utilized in the final design.

• Estimated total thrust requirement = 11,500 lbf.• Turbofan, Turboprop, and UDF engines are among the

considerations.• Engines will be modeled based on existing platforms.• The design concepts intend to combine the use of two types

of engines, so the effects of separate and simultaneous use will need to be determined.

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Turbofan

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PROS• Efficient at subsonic speeds• Lower TSFC• Low direct operating cost• Commercially acceptable

technical risk• Relative mechanical

simplicity• Proven technology

CONS• Weight, drag of large

diameter fan and nacelle

Turboprop

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PROS• Efficient at cruising altitude,

can be more efficient than turbofan

• High potential for fuel savings

CONS• Speed limited to M < 0.65• High noise and vibration

UDF

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PROS• High potential for fuel

savings

CONS• Speed limited to M < 0.85• High noise and vibration• Only a few existing designs

Engine Modeling - Turbofan

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• Baseline engine is HF120 Turbofan• Manufactured by GE Honda Aero Engines• Environmentally Friendly:

a) Designed to reduce NOx, CO, HC, and smoke emissions.b) Meets Stage 4 noise level requirements with room to

spare.

Turbofan Cont’d

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Engine Modeling - Turboprop

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• Baseline engine is the Rolls-Royce M250-B17.• Combines small size and a high power to weight

ratio.

Turboprop Cont’d

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• Specifications:

Width 19.4 inLength 45 inWeight 212 lb

Engine Modeling - UDF

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A few concepts have been built in the past, including: GE-36, P&W-578DX, and the Russian built Progress-D27.

GE-36 Progress-D27

UDF Cont’d

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• Very little data exists for the unducted fan engines. • The 3 examples of unducted fans shown were meant

for much higher thrust outputs than a business jet requires.

• Currently working on an accurate method for predicting performance and scaling to fit the business jet design.

Modeling of Baseline Engines

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• The three engines shown are the baseline engines that will be scaled to meet the final design’s needs.

• The engines will be scaled for proper thrust and fuel flow, while incorporating technology factors to predict performance in 2020.

Technology Factor

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• According to historical data, seat miles per gallon increased from 26.2 to 49 for small commercial aircraft between 1970-1989.

• Improving seat miles per gallon would require the improvement of many individual technologies, and therefore is a good estimate of the overall technological advancement rate.

• Seat miles per gallon improved by 3.3 %/yr between 1970-1989.

• To be conservative, our design will be based on an assumed overall technological improvement rate of 2 %/yr.

Center of Gravity, Stability, Control Estimates

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Concept 1 Concept 2

Location of c.g. 27.7 ft 28.6 ft

Location of a.c. 28.9 ft 30.3 ft

Static Margin 1.2 ft 1.7 ft

**c.g. travel diagram is not yet calculated

0 5 10 15 20 25 30 35 40 45 50

-40

-30

-20

-10

0

10

20

30

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0 5 10 15 20 25 30 35 40 45 50

-40

-30

-20

-10

0

10

20

30

40Center of Gravity

Neutral Point

Tail Sizing

• Current approach– Design tail so that the a.c. is close to c.g.– More calculation needs to be done

• Current estimated size

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Concept 1 Concept 2

Tail area 80 ft2 70 ft2

Vertical Tail area 80 ft2 100 ft2

Cabin Layout

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Cabin Layout Cont’d

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Concept 1 CATIA

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Concept 2 CATIA

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Compliance Matrix

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Requirement Target Threshold Concept 1 Compliant Concept 2 Compliant

Maximum Mach Number 0.85 0.8 0.8 Yes 0.8 Yes

Empty Weight (lb) 18,500 20,000 16,700 Yes 15,100 Yes

Gross Weight (lb) 28,000 32,000 34,100 No 32,700 No

Takeoff Distance (ft) 3,400 3,800 4,100 No 4,000 No

Maximum Range (nmi) 3,700 3,600 3,640 Yes 3,700 Yes

Design Mission Range (nmi) 3,700 3,600 3,640 Yes 3,700 Yes

Noise (dB) 42 50 77 No 77 No

Seats 10 8 8 Yes 8 Yes

Volume Per Passenger (ft^3) 65 60 60 Yes 60 Yes

TSFC (% of avg) 55 65 65 Yes 65 Yes

N0X Emissions (% of avg.) 25 50 10 Yes 10 Yes

Charge Time - 220V 80A* (hr) 2 4 1.5 Yes 1.5 Yes

Charge Time - 125V 15A** (hr) 3 5 4 Yes 4 Yes

Internal Systems Power (kWh) 5 6.5 8 No 8 No

Next Steps?I. Select the best conceptII. More accurate sizing

a) Detailed sizing codeb) Detailed model of the conceptc) Accurate weightsd) Control Surface area calculation

III. Trade-offs for the selectionIV. Determine specific details of the Aircraft

a) Propulsion, Aerodynamics, Structureb) Noisec) Costd) Performancee) Stability / Control Calculation

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