1. October 30, 2001A&AE 451 - Fall, 20011 Critical Design Review Brian Barnett Rob Benner Alex Fleck Ryan Srogi John Keune

2. October 30, 2001A&AE 451 - Fall, 20012 Preliminary Design Initial Weight Estimation (Historical Data) –Payload = approx 1.18 lb 3 Battery Cells Rate Gyro –Weight = approx 5 lb.

3. October 30, 2001A&AE 451 - Fall, 20013 Preliminary Design Equations of Constraint (Roskam) –Loiter Velocity –Turn Radius –Climb Angle

4. October 30, 2001A&AE 451 - Fall, 20014 Preliminary Design Equations of Constraint (Roskam) –Ground Roll –Stall

5. October 30, 2001A&AE 451 - Fall, 20015 Preliminary Design Constraint Diagram W/P = 23 lb/hp W/S = 0.55 lb/ft 2 With AR=6, S = 9.1 ft 2 b = 7.4 ft c = 1.2 ft

6. October 30, 2001A&AE 451 - Fall, 20016 Aerodynamics Airfoil Selection –Best endurance when C L 3/2 /C D is maximized –Selig airfoils for low Re flight –2-D Data readily available online (www.nasg.com) –Compared 13 Selig airfoils Roskam method used to generate C L and C D values

7. October 30, 2001A&AE 451 - Fall, 20017 Aerodynamics Selig S1210 Airfoil

8. October 30, 2001A&AE 451 - Fall, 20018 Aerodynamics Twist for elliptical loading Elliptical Loading 12º total twist Very high d  /dy near wing tips Twist for elliptical loading very difficult to manufacture Linear Twist 3º twist is sufficient to ensure initial stall at root Angle of incidence C L 3/2 /C D peaks at 3º

9. October 30, 2001A&AE 451 - Fall, 20019 Aerodynamics Vertical Tail Sizing (Roskam) Aerodynamics

10. October 30, 2001A&AE 451 - Fall, 200110 Longitudinal Xplot SM = 15% Horizontal Tail Area = 1.7 ft 2 Xcg = 0.37c Xac = 0.52c Aerodynamics

11. October 30, 2001A&AE 451 - Fall, 200111 Propulsion Power Analysis P req = P pout = P pin *  p P pin = P gout P gout = P gin *  g P gin = P mout P mout = P min *  m P min = P bout Battery Speed Controller MotorGearboxPropeller pp gg mm P pout P gout = P pin P mout = P gin P bout = P min

12. October 30, 2001A&AE 451 - Fall, 200112 Propeller Selection Power required from aerodynamics 8.6 ft*lb f /sec Gold matlab code 15 x 10 propeller was chosen n = RPM/60 = Hz D = propeller diameter  p =.766 Propulsion

13. October 30, 2001A&AE 451 - Fall, 200113 Propulsion Effect of Differing Prop Diameter with Pitch = 10” Prop Eta Power Out (ft*lb f /sec) RPM =1910 Eta =.766 Ground Clearance Constraint (15”) D=8” D=18” D=16” D=14” D=12” D=10” Power Required=8.6

14. October 30, 2001A&AE 451 - Fall, 200114 Gearbox Selection P pin = P gout = 11.23 ft*lb f /sec P gin = P gout /.95 = 11.82 ft*lb f /sec Gear ratio = 3:1  g =.95 Propulsion

15. October 30, 2001A&AE 451 - Fall, 200115 Propeller Selection Power required from aerodynamics 8.6 ft*lb f /sec Gold matlab code 15 x 10 propeller was chosen Propulsion n = RPM/60 = Hz D = propeller diameter J = V/(n*D)  p = Ct*J/Cp =.766

16. October 30, 2001A&AE 451 - Fall, 200116 Motor Selection P gin = P mout = 11.82 ft*lb f /sec RPM = 1910 Matlab script was run for 615 motors Motor was chosen for highest efficiency using three battery cells Propulsion Efficiencies  m =.519  g =.95  p =.766  tot =.378

17. October 30, 2001A&AE 451 - Fall, 200117 Motor Performance Motor Current (amperes) Propulsion

18. October 30, 2001A&AE 451 - Fall, 200118 Battery Selection 3 x Panasonic NiMH batteries 3000 mAh 1.2 V/cell 57.4 g/cell Propulsion

19. October 30, 2001A&AE 451 - Fall, 200119 Propulsion Maxx Products Cobalt 400 14T Kv = 2290 RPM/V Io = 2.5 A Imax = 20 A Rm =.108 Ohm $70.00 Maxx Products Ball Bearing Gearbox Ratio 3:1 $22.50

20. October 30, 2001A&AE 451 - Fall, 200120 Finite Element Methods Modeling Moment of Inertia: I = 2(A flange x d 2 ) + 1/12 (b web x h 3 web ) 3/8” 1/8” 3/8” All Spars Structures

21. October 30, 2001A&AE 451 - Fall, 200121 Bending Load Carried in Spars Huge percentage of bending moment transmitted to all spars Max stress:  max = M max y I Uniform Pressure Load: 2.5 lbs x 2.5 g’s = 6.25 lbs 6.25 lbs x 1.5 safety factor = Applied Load = 9.38 lbs Divided by ½ Wing Area: 9.38 lbs / 648 in 2 = Distributed Pressure Load =.0145 psi Structures

22. October 30, 2001A&AE 451 - Fall, 200122 FEM Calculated Weight:.56 lbs for ½ wing Exaggerated Wing Deflection FEM Results:  max = 273.3 psi  max =.34” Balsa Properties:  yield = 1725 psi (WT team, Spring ’99) Structures

23. October 30, 2001A&AE 451 - Fall, 200123 Buckling Load: FEM calculates Eigenvalue of stability problem This value is a load multiplier for buckling to occur Wing Spar Buckling Point E value = 5.443 Applied Load =.0145 psi Buckling Load =.0789 psi Structures

24. October 30, 2001A&AE 451 - Fall, 200124 Fuselage Structure Employing bulkheads/stringers for ease of manufacturing Tail-boom to be captured through reinforced bulkheads Terminates at wing bolt-down block Pinned to prevent rotation Removable at fuselage junction Structures

25. October 30, 2001A&AE 451 - Fall, 200125 Tail Structure Built on a box design Hole drilled into box to allow tight fit of tail-boom Pinned design prevents rotation Stabilizer assembly removable from boom Stabilizers manufactured from sheet balsa with lightening holes Structures

26. October 30, 2001A&AE 451 - Fall, 200126 Landing Gear Structure Steerable nose-wheel mounted to internal firewall Main gear mounted to internal/external sandwich plate Bolt holes run vertically between stringers Minimize damage if shear-off occurs Easily replaceable Structures

27. October 30, 2001A&AE 451 - Fall, 200127 Control Surface Sizing Class I sizing based on historical data Dynamics & Control

28. October 30, 2001A&AE 451 - Fall, 200128 Dihedral and Static Margin 2º dihedral recommended for high-wing model aircraft with ailerons and no sweep. –‘The Basics of R/C Model Aircraft Design’ 15% Static Margin –Mark Peters recommends 18% –Previous 451 designs have gone as low as 10% –Adjustable by moving internal components Dynamics & Control

29. October 30, 2001A&AE 451 - Fall, 200129 Loop Closure K H g (s) Rate Gyro Transfer Function Feedback Gain H e (s) q(s)/  e (s)  Servo Transfer Function Aircraft Transfer Function + -  e (s) q(s) Pilot Input Dynamics & Control

30. October 30, 2001A&AE 451 - Fall, 200130 Transfer Functions Aircraft Transfer Function (Short Period Approximation) Natural Frequency and Damping Ratio = 6.63 rad/s = 1.146 Dynamics & Control

31. October 30, 2001A&AE 451 - Fall, 200131 Transfer Functions Futaba S-148 Servo Transfer Function (2 nd Order Approximation) Airtronics SG-1 Gyro System Gain K (abs value) < 1.3 deg/(deg/sec) Dynamics & Control

32. October 30, 2001A&AE 451 - Fall, 200132 Root Locus Dynamics & Control

33. October 30, 2001A&AE 451 - Fall, 200133 Bode Plot Dynamics & Control

34. October 30, 2001A&AE 451 - Fall, 200134 Nyquist Plot Dynamics & Control

35. October 30, 2001A&AE 451 - Fall, 200135 Flight Testing Schedule of Events

36. October 30, 2001A&AE 451 - Fall, 200136 Component Testing Test boom for structural strength with point load at end of boom Test wing with uniform load distribution Landing gear test for impact load carrying Provides time to add strength if needed before flight Engine test on stand, check operation Control Surface test, check operation Flight Testing

37. October 30, 2001A&AE 451 - Fall, 200137 Ground Testing Phase 1 (AR 106) Ground Stability Check Phase 2 (Black IM Fields) Running takeoff, feedback off, turns, climbs, descents, approaches to landing Rolling Takeoff Phase 3 (Smooth Surface Strip) Stabilizing feedback on, turns, climbs, descents, approaches to landing Phase 4 (Smooth Surface Strip) Destabilizing feedback, turns, climbs, descents, approaches to landing Phase 5 (Smooth Surface Strip) Confined space practice, endurance test Phase 6 (Mollenkopf) Stabilizing and destabilizing feedback, indoor endurance test Flight Testing

38. October 30, 2001A&AE 451 - Fall, 200138 Approximate cost for boom $25 This is available at Hobby Time Approximate cost for landing gear $20 This is available at Tower Hobbies Brings total cost to approximately $198 Cost & Economics

39. October 30, 2001A&AE 451 - Fall, 200139 Man-hours devoted Includes time spent in classroom. Total hours spent: 985 hrs Man hours per person per week: 17.9 hrs Project 600 man hours for construction Cost & Economics

40. October 30, 2001A&AE 451 - Fall, 200140 Prototype Cost: $119,073 985 design hours + 600 construction hours 1585 prototype development hours Further Production Cost: $257.54 Sell 2000 aircraft kits Prototype costs/2000 kits + kit price $75.00 per hour labor cost Kit Price = $198.00 Cost & Economics

41. October 30, 2001A&AE 451 - Fall, 200141 Questions?

42. October 30, 2001A&AE 451 - Fall, 200142 Appendix 3-View Drawing

43. October 30, 2001A&AE 451 - Fall, 200143 Appendix Roskam Method:

44. October 30, 2001A&AE 451 - Fall, 200144 Appendix

45. October 30, 2001A&AE 451 - Fall, 200145 Effect of Differing Prop Diameter with Pitch = 6” Power Out (ft*lb f /sec) Prop Eta RPM =2430 Eta =.757 Ground Clearance Constraint (15”) D=8” D=18” D=16” D=12”D=10” D=14” Power Required =8.6

46. October 30, 2001A&AE 451 - Fall, 200146 Effect of Differing Prop Diameter with Pitch = 8” D = 8” D=1 2” D=1 0” D=1 8” D=1 6” D=1 4” Power Out (ft*lb f /sec) Prop Eta RPM =2140 Eta =.765 Ground Clearance Constraint (15”) Power Required=8.6

47. October 30, 2001A&AE 451 - Fall, 200147 Effect of Differing Prop Diameter with Pitch = 12” Power Out (ft*lb f /sec) Prop Eta Ground Clearance Constraint (15”) D=8” D=10 ” D=12 ” D=14 ” D=16 ” D=18 ” RPM =1750 Eta =.760 Power Required=8.6

48. October 30, 2001A&AE 451 - Fall, 200148 Dimensional Derivatives

49. October 30, 2001A&AE 451 - Fall, 200149 Stabilizing Root Locus

50. October 30, 2001A&AE 451 - Fall, 200150 Stabilizing Bode Plot

51. October 30, 2001A&AE 451 - Fall, 200151 Stabilizing Nyquist Plot

52. October 30, 2001A&AE 451 - Fall, 200152 Step Response