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Preliminary Design Review EcoJet. Group 2. Mike Dumas Adam Naramore Ben Scott. Gaetano Settineri Tim Sparks David Wilson. Market. Target buyers are fractional ownership operators Market Capture Target (Next 5 Years) 2.5% Total Market 25 Aircraft Growth Estimates (5+ Years)
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Preliminary Design ReviewEcoJet Group 2 Mike Dumas Adam Naramore Ben Scott Gaetano Settineri Tim Sparks David Wilson
Market • Target buyers are fractional ownership operators • Market Capture Target (Next 5 Years) • 2.5% Total Market 25 Aircraft • Growth Estimates • (5+ Years) • 5% Total Market or 50 Aircraft • Growth Forecast (By 2022) • 7% Light-Medium Market or 260 Aircraft
3-view 55ft 7 ft 13ft 50ft 100
Cabin Layout Sleeper Seats Closet Seats Lavatory Cockpit Refreshment Center Door
Sizing • GTOW: 26,144 lbs • W/S: 70 lb/ft2 • T/W: 0.45 lbf/lbm • AR: 8.3 • Wing sweep: 30 degrees • Taper Ratio: 0.32 • Dihedral: 10.3 degrees
Flops Sizing • Flops Analysis • Gross Takeoff Weight Max = 30,000 lbs • W/S = 65 - 75 lb/ft^2 • T/W = 0.4 - 0.5 (output of approx. 5751.7 lbf/engine) • Analysis done with Fixed Mach # and Altitude • Cruise Mach # = 0.85 • Cruise Alt.= 41,000 ft. • IFR range accounted for in flops • 100 nm. Alternate airport range • 45 min. Loiter
Drag Polars: From Flops Mach #
Drag Polar Comparison Good Comparison between FLOPS Data and Raymer Code • Reasons for Error: • Inaccurate Raymer Wave Drag Approx. • No FLOPS airfoil input • Inaccurate Span Efficiency
V-N Diagram Load factor (g’s) Stall Speed Velocity (ft/sec)
Structural Layout • Wing box occupies 7-70% of the chord length • Wing box carries through the fuselage • Ribs are spaced 5 ft apart • Spar web thickness: 0.25 in • Forward wing spar flange thickness: 0.5 in • Aft wing flange thickness: 0.4in • Rib thickness: 0.2 in
Materials • Wing/Fuselage Skin: AS4/3501-6 Graphite Epoxy • Quasi-isotropic lay-up: [±45/0/90]s2 • Ply thickness: 0.005 in • Wing Box/Ribs: Al 2017
C. G. and Weight Estimates Utilized Equations from Raymer, Chapter 15 Weights from Cargo/Transport Category were Averaged with Weights from GA Category Location of the CoM for each Component was Estimated from 3-D Model Static Margin was Calculated as a Percent of the MAC Static Margin Limits were taken from Course Notes for Stanford University AAE241 (http://adg.stanford.edu/aa241/stability/staticstability.html)
Propulsion • Fuel: B100 Bio-diesel • Estimated Max TO thrust: ~5300 lbs/engine • Overall Pres. Ratio = 20 • Fan Pres. Ratio = 2.9 • Bypass Ratio = 3.2 • Best SFC: 0.88 lbm/lbf/hr • Garret’s TFE731-60 engine
Cost Analysis • Final Estimated DOC: $1,062/hr • Final Estimated Acquisition Cost: $14.5 mil • Developed from: • FLOPS • Historical data • Estimates of new technology and design factors
Summary • Open issues: • Reduce GTOW • Fuel Testing • Acquisition Cost • Optimization of wing structure • CFD
Airfoil Choice • Over 40 Airfoils Compared • Wings – NACA 64212 • Wing Elevator Section & Vertical Tail – NASA - SC20010
Reynolds Number • Based on 41,000 ft at 480 kts Fuselage – 7.59 x 107 Fore Wing – 2.74 x 105 Aft Wing – 2.19 x 105