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AAE 451 Aircraft Design. First Flight Boiler Xpress November 21, 2000 Team Members Oneeb Bhutta, Matthew Basiletti , Ryan Beech, Mike Van Meter Professor Dominick Andrisani. 3-D Views. 11ft. 6ft. Aerodynamic Design Issues. Lift Low Reynolds Number Regime Slow Flight Requirements
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AAE 451 Aircraft Design First Flight Boiler Xpress November 21, 2000 Team Members Oneeb Bhutta, Matthew Basiletti , Ryan Beech, Mike Van Meter Professor Dominick Andrisani
3-D Views 11ft 6ft
Aerodynamic Design Issues • Lift • Low Reynolds Number Regime • Slow Flight Requirements • Drag • Power Requirements • Accurate Performance Predications • Stability and Control • Trimmability • Roll Rate Derivatives
Low Reynolds Number Challenges Separation Bubble-to be avoided! • Laminar Flow -more Prone to Separation • Airfoil Sections designed for Full-sized Aircraft • don’t work well for below Rn=800,000 • Our Aircraft Rn=100,000-250,000
Airfoil Selection Wing: Selig S1210 CLmax = 1.53 Incidence= 3 deg Tail sections: flat plate for Low Re Incidence = -5 deg
Drag Prediction • Assume Parabolic Drag Polar Based on Empirical Fit of Existing Aircraft
Parasite Drag Drag Build-up Method of Raymer (Ref. Raymer eq.12.27 & eq.12.30) Blasius’ Turbulent Flat Plate- Adjusted for Assumed Surface Roughness
Aircraft Drag Polar 0.16 CD CDi 0.14 CDo 0.12 0.1 0.08 0.06 0.04 0.02 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 CL Drag Polar
32 30 28 26 24 Power Required [ft-lb/s] 22 20 18 16 15 20 25 30 35 40 Velocity [ft/s] Power Required • Predict: • Power required for • cruise • Battery energy for • cruise
Aerodynamic Properties Wetted area = 44.5 sq.ft. Span Efficiency Factor = 0.75 CLa=5.3 / rad CL de =0.4749 /rad L/Dmax = 15.5 Vloiter = 24 ft/s CLmax = 1.53 CLcruise = 1.05 Xcg = 0.10-0.38 (% MAC) Static Margin = 0.12 at Xcg = 0.35
0.3 elev deflect=-8 deg -4 0 0.2 4 8 0.1 elev deflect=-8 deg -4 0 0 4 Cmcg 8 -0.1 -0.2 -0.3 -0.4 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 CL Stability Diagram
Parasite Drag • CDo for Wing and Tail surfaces • For Fuselage, booms & pods (Ref. Raymer eq.12.31 & eq.12.33)
Tail Geometry Horizontal Tail: Area = 2.2 Span = 3.0ft Chord = 0.73ft Vh = 0.50 Vertical Tail- 25% added Area = 1.75 sq.ft Span = 1.63 ft Chord = 0.60 ft Vv = 0. 044
Control Surface Sizing: Elevator Area Ratio = 0.30 Chord = 2.7 in. Rudder Area Ratio = 0.40 Single rudder of chord = 7.5 in. Ailerons Area Ratio = 0.10 Aileron chord = 3 in.
Rotation angle = 10deg Controls equipment Propulsion component 17.54 in. Airframe component Tip Back angle= 15deg Miscellaneous Weight Equipment Layout & CG.
Vvert=2.2ft/s g = -5 deg Landing Loads Vland=1.3Vstall=25ft/s For d = 1 in., k = 15.2 lb/in For 1 inch strut travel, peak load = 15.2 lb sspar = 240 psi on landing
Static Margin, Aerodynamic Center, and c.g. Xac = 0.46 Xcg = 0.35 SM = 0.11
Horizontal and Vertical Tail Sizing Vh - Horizontal tail volume coefficient = 0.50 Vv - Vertical tail volume coefficient = 0.044
Control Surface Sizing • Based on historical data from Roskam Part II Tables 8.1 and 8.2. Homebuilts Single Engine 0.095 0.08 0.42 0.36 0.44 0.42
Control Surface Sizing (cont.) • Sa = 1.35ft2 • Sr = 0.80ft2 • Se = 1.00ft2 • Max. surface deflection is 15 deg.
Climb Performance • Max. Climb Angle, G G = 7.3 deg.
Turning Performance • Maximum turn rate r = 50ft Vmax = 28ft/s Y= 0.28rad/s
Propulsion Design Issues • Power • Power required • Power available • Endurance • Can we complete the mission • Verification • Motor test to take place this week
Power • Power required is determined by aircraft • Power available comes from the motor
System Efficiencies • Propeller • 60-65% • Gearbox • 95% • Motor • 90% • Speed Controller • 95% Total System Efficiency 50.7%
System Components • Propeller • Freudenthaler 16x15 and 14x8 folding • Gearbox • “MonsterBox” (6:1,7:1,9.6:1) • Motor • Turbo 10 GT (10 cells) • Speed Controller • MX-50
Economics • Preliminary Design • 525 man-hours @ $75 = $39,375 • Testing • 50 man-hours @ $75 = $3,750 • $81.70 in materials
Economics • Prototype Manufacturing • 300 man-hours @ $75 = $22,500 • $417.35 in materials • Flight Testing • $900 • Prototype manufacturing budget • $200 max
Total Project Cost • The Bottom Line $67,024.05