1. The Barn Owls Chris “Mo” Baughman Kate Brennan Christine Izuo Dan Masse Joe “Sal” Salerno Paul Slaboch Michelle Smith

2. Design Drivers High Rate of climb Max. cruise speed

3. Motivation To build an aircraft which will take off (multiple times without crashing) Accurately predict the performance of the designed aircraft Maximize the speed and rate of climb

4. Guidelines and Limitations 400 – 800 sq. in. planform area Given Astro-Cobalt 615G motor Must be statically stable Takeoff run < 300 ft. No rockets!?!?!?!?!?!?!?!?!?!?!?!?!?!?!?

5. Schedule and Deadlines February 5 th – Present Conceptual Design February 26 th – Present Detailed Design March 4 th – Complete Parts List April 6 th -9 th – Ground Tests

6. Weights Structure (estimation)1.5 Misc. (glue, monokote, screws)0.4 Engine (Cobalt 15)0.56 Propeller0.06 Servo (5)0.50 Receiver & Battery0.25 GPS & Transmitter0.5 Electronics Box1.5 Speed Controller0.08 Main Battery0.65 Total (lbs.):6.0

7. Powerplant Model No.p/n 615G Name05 Geared Gear Ratio2.38 to 1 Armature Winding7 turns Armature Resistance0.069 ohms Magnet TypeSm Cobalt BearingsBall Bearings Motor Speed1488 rpm/volt Geared Motor Speed652 rpm/volt Motor Torque/amp0.91 in-oz /amp Geared Torque2.17 in-oz /amp Voltage Range8 to 12 volts No Load Currrent2 amps Maximum Continuous Current25 amps Maximum Continuous Power400 watts Gear Motor Length3.3 inches Motor Diameter1.3 inches Motor Shaft Diameter5/32 inch Prop Shaft Diameter1/4 inch Gear Motor Weight9 oz www.astroflight.com

8. Thrust VS Speed

9. Airfoil – GO 769 Cl max 1.7000 Cl  0.0916 a.c.0.2500  0L -6.0000 Cd 0 0.0100 r le 0.0470 Cl minD.22 - 1.22 (t/c) max 0.1330

10. Design Factors in Choosing Airfoil Appropriate Reynolds Number Data (low speed) Minimize Drag –t/c ~ 14% –wide drag bucket –Shallow increase in drag outside of drag bucket Maximize Lift –High C L max

11. Wing Design Decisions No sweep Maximize lift Ease of manufacture Taper ratio of 0.25 Minimize drag Create large enough root chord length in order to provide clearance for payload Slight dihedral for roll stability Winglets enhance in-flight performance

12. Fuselage Airfoil-shaped fuselage serves as lifting surface Also serves as a wing box which carries electronics Conventional fuselage has been replaced by booms on order to minimize weight and drag

13. Horizontal Tail NACA 0009 Airfoil –Low drag, symmetric –Can Produce both Lift and Reverse Lift –Swept to maintain straight trailing edge to maximize control surface while minimizing planform area

14. Take-off/Landing Estimations Take-off Distance = 176 ft. Landing Distance = 370 ft. (does not take into consideration climbing over an obstacle)

15. Flaps Slotted, 15% of total wing area Used as flaperons –Enhanced lift for take-off –Control during flight –Speed brakes during landing

16. Weight Distribution Load Summary (fuselage) Load TypeMagnitudex/L_startx/L_end resultantM @C_liftdw (lbs) x/Lf-lb (+ cw) Fuel2.0000.180.09-0.44480.434783 Payload10.180.360.270.02780.217391 Fus.Struct.0.53010.50.1837730.025183 Engine(s)0.5000.180.09-0.11120.108696 Wing Struct.0.56010.50.1944130.026641 Horiz. Tail0.032.22.42.30.0866540.006082 Vert. Tail0.032.22.42.30.0871690.006118 Other0.5600.050.025-0.174040.278247  L 5.205802  M -0.15023 Tail Lift (req)-0.052722.22.42.3-0.15023-0.01054

17. Static Stability Static Margin: 0.029753 (stable) C M,α = -0.78423 (stable) C N,β = 0.015653 (stable) C Lβ = -0.015653 (stable)

18. Conclusions