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Systems Design Review Presentation. Joe Appel Todd Beeby Julie Douglas Konrad Habina Katie Irgens Jon Linsenmann David Lynch Dustin Truesdell. Outline. Mission statement Design requirements Concept generation and selected concepts Technology and effects
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Systems Design Review Presentation Joe Appel Todd Beeby Julie Douglas KonradHabina Katie Irgens Jon Linsenmann David Lynch Dustin Truesdell
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
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
Major Design Requirements • NASA ERA Goals Large twin aisle reference configuration = Boeing 777-200LR
Major Design Requirements • Market Goals • 200 passengers • Intra - Continental Range • 3200 Nautical Miles • Operability • Maintenance • Turnaround time • Production and operating costs
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
Technologies • Concept 1: • “Double bubble” fuselage • C - wing • Aft mounted engines • Concept 2: • High wing • Under wing engines • High aspect ratio wing
Technologies • On both concepts • Laminar flow • Composite Materials Courtesy NASA
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
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
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
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
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 Courtesy GE Aircraft Engines
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
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%)
Basic Assumptions • Concept 1 – Double Bubble • Concept 2 – High Wing
Constraint Diagram: Concept 1 Tsl/W0 = 0.29 (lbf/lb) W0/S = 103 (lbs/ft2)
Constraint Diagram: Concept 2 Tsl/W0 = 0.26 (lbf/lb) W0/S = 84 (lb/ft2)
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
Aircraft Design Mission 3 Norange descent CruiseClimb Loiter (30 min) Loiter (30 min) 2 6 7 No range descent Climb 32000 ft Climb 4’ 5’ 0 Attempt to Land 5 9 1 4 8 Taxi & takeoff Land Land 6800 ft Range: 3200 nmi 4950 ft Fuel Reserves
Code Status Current Status Validated Code for Boeing 757-200 and 767-200ER Split up sizing code into weight and drag components Location of center of gravity for Hybrid Concepts Validation using similar a/c: Boeing 757-200 TOGW = 255000 lb, OEW = 127000 lb, Wfuel = 74510 lb
Basic Assumptions • Concept 1 – Double Bubble • Concept 2 – High Wing
Sizing Approach • 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
Concept Descriptions • Concept 1 – Double Bubble • Concept 2 – High Wing
Component Weight Breakdown Double Bubble High Wing
Sizing Output Double Bubble High Wing
Center of Gravity • Concept 1 – Double Bubble Static Margin = -20 a.c. 93’ c.g. 73’ Datum 65’ 69’ 122’ 125’ 130’
Center of Gravity • Concept 2 – High Wing Static Margin = -18 a.c. @ 88’ Datum c.g. @ 70’ 56’ 69’ 75’ 145’ 150’
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
Concept 1: Exterior 15.6’ 130’ 160’ 20’
Concept 1: Interior • Cabin height = 7ft 2in
Concept 2: Exterior 17.8’ 150’ 231’ 17.5’
Concept 2: Interior • Cabin height = 7ft 2in
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
Concept Generation & Selection • House of Quality