1. Project Presentation Boiler Xpress December 5, 2000 Team Members Oneeb Bhutta Matthew Basiletti Ryan Beech Micheal Van Meter AAE 451 Aircraft Design

2. Presentation Overview Design Mission Concept Selection & Initial Sizing Detailed Analysis: Aerodynamics Structures Propulsion Stability, Dynamics, and Control Conclusions

3. The Mission Variable Stability Aircraft- Roll Axis 1.2 lb payload Flight Within Mollenkopf Athletic Ctr: 20 ft/s stall speed 12 minute Endurance/ electric power plant Robust and Affordable Transportable Airframe cost < $200

4. Flight Mission 5.5 deg Climb Angle 35 ft Radius 120 ft. max T.O. roll 10 second “Straight Line” 42’ Ceiling height

5. 1 23 4 5 Objective Score% of Total Rank Endurance3010.07 Build within 3 weeks10.09.164 Light weight27.516.661 Turning radius9.1616.662 Robustness50106 Transportability16.6649 Ease of analysis507.58 Landing ability16.662.6610 Maintainability30105 Marketability1013.333 Weighted Objectives Method

6. Constraint Diagram

7. Initial Sizing

8. Geometry and Configuration Wing: Sref = 13.5 sq.ft. Span = 11 ft. Aspect Ratio = 9 Taper Ratio = 0.6 tip section Airfoil: S1220 Horizontal Stabilizer: Area = 1.83 sq ft. Span = 3.0 ft. Vertical Stabilizer: Total Area: 1.15 sq.ft. Boiler Xpress 11.1’ 5.8’

9. Aerodynamic Design Issues Lift Low Reynolds Number Regime Slow Flight Requirements Drag Power Requirements Accurate Performance Predications Stability and Control Trimmability Roll Rate Derivatives

10. Low Reynolds Number Challenges 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 Separation Bubble-to be avoided!

11. Airfoil Selection Wing: Selig S1210 CLmax = 1.53 Incidence= 3 deg Tail sections: flat plate for Low Re Incidence = -5 deg

12. Drag Prediction Assume Parabolic Drag Polar Based on Empirical Fit of Existing Aircraft

13. Parasite Drag (Ref. Raymer eq.12.27 & eq.12.30) Drag Build-up Method of Raymer Blasius’ Turbulent Flat Plate- Adjusted for Assumed Surface Roughness

14. Drag Polar

15. Power Required Predict: Power required for cruise Battery energy for cruise

16. Aerodynamic Properties Wetted area = 44.5 sq.ft. Span Efficiency Factor = 0.75 CL    =  5.3 / rad CL  e = 0.4749 /rad L/D max = 15.5 V loiter = 24 ft/s CL max = 1.53 CL cruise = 1.05 Xcg = 0.10-0.38 (% MAC) Static Margin = 0.12 at Xcg = 0.35

17. Stability Diagram elev deflect=-8 deg -4 0 4 8 00.20.40.60.811.21.41.61.8 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 CL Cmcg elev deflect=-8 deg -4 0 4 8

18. Flow Simulation

19. Parasite Drag C Do for Wing and Tail surfaces (Ref. Raymer eq.12.31 & eq.12.33) For Fuselage, booms & pods

20. Structures Outline Materials Employed for the structure Mathematical Model Bending Moment & Stresses; Wing Test Equipment layout Landing Gears & Landing Loads

21. Structural Materials Styrene foam wing core Balsa spars carry bending load 0.25 in x 0.25 in T.E. Reinforcement

22. Materials Employed

23. Wing

24. Mathematical Model Wing Assumptions: Wing and Weight loading Method of Analysis (Theoretical Model) 2.5g x 1.5 P Boom Horizontal Tail

25. Bending Moments Max Moment = 41.71 lbf/ft

26. Stresses in Wing Sigma max = 2003 psi Sigma critical = 1725 psi (Actual Test Result; Whiskey Tango Team, Spring 1999) Reasons:  Light Weight Structure  Safety Factor (worst case scenario)  Wing Test Results 1.5ft P

27. Horizontal Tail & Boom Horizontal Tail: Max Stress = 850psi Spar Sizes = 1/8 in x 1/16in Booms: Max deflection = 0.24 in @ 2.5g’s x 1.5 Assuming Young Modulus (E) for a Carbon Epoxy matrix. Testing needed to verify result. Material & Time Constraint

28. Equipment Layout & CG. CG. = 30%~38% MAC (Predicted) CG. = 35% MAC (Actual)

29. Landing Gear From Raymer. Method of Sizing and placement of Landing gears Nose Gear: (3’’ from nose) Main gears: -6’’ from leading Edge -Separation (1.5 ft)

30. V land =1.3V stall =25ft/s For d = 1 in., k = 15.2 lb/in  = -5 deg V vert =2.2ft/s For 1 inch strut travel, peak load = 15.2 lb  spar = 240 psi on landing Landing Loads

31. Propulsion Design Issues Power Special needs Endurance Propulsion system tests

32. Power Power required is determined by aircraft Power available comes from the motor

33. Special Needs Pusher configuration Adjustable timing motor Reversible motor Propeller High efficiency for endurance Special propeller for electric flight

34. 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

35. System Efficiencies Propeller 60-65% Gearbox 95% Motor 90% Speed Controller 95% Total System Efficiency 50.7%

36. Propulsion Tests

37. Torque Sensor Motor/Prop To Batteries Test Stand Attached to Wind Tunnel Balance

38. Aircraft Analysis Best Endurance Speed V e = 23.2 ft/s Power Required at Best Endurance Speed P r = 15.62 ft-lb/s

39. Flight Performance Increased weight 17% increase Increased cruise flight speed 22% increase Lift coefficient 26% decrease Endurance/Power 42% decrease in endurance

40. Flight Performance, Stability & Control Sizing of horizontal and vertical tails and control surfaces Location of c.g. and aerodynamic center Determination of static margin Roll-axis block diagram Transfer functions Flight Performance Data

41. Horizontal and Vertical Tail Initial Sizing V h - Horizontal tail volume coefficient = 0.50 V v - Vertical tail volume coefficient = 0.044 (8.3) (8.4)

42. Control Surface Sizing Based on historical data from Roskam Part II Tables 8.1 and 8.2. HomebuiltsSingle Engine 0.095 0.08 0.42 0.36 0.44 0.42

43. Dihedral Angle Paper by William McCombs suggests 0 – 2 degrees for RC aircraft with ailerons. Estimated by Raymer for a mid-wing aircraft to be 2 – 4 degrees. Our Aircraft- 2 degrees

44. X-plot Horizontal Tail X ac = 0.46 X cg = 0.35 SM = 11% MAC -Used to find elevator area for desired Static Margin

45. X-plot Vertical Tail 0.40.60.811.21.41.61.8 -0.4 -0.2 0 0.2 0.4 0.6 Vertical tail area [sq ft] CnBeta Used to determine Weathercock stability (yaw) C n  = 0.11

46. Flight Performance

47. Tx Rx1 k + P Block Diagram – Roll Axis ServoAircraft Gyro

48. Dynamic Modeling = 0.80 = -0.15

49. Root Locus -90-80-70-60-50-40-30-20-1001020 -80 -60 -40 -20 0 20 40 60 80 Real Axis Imag Axis De-stabilizing feedback

50. Nyquist Diagram Real Axis Imaginary Axis Nyquist Diagrams -0.8-0.6-0.4-0.200.20.4 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 From: U(1) To: Y(1) K = 0.3655 Gm=25.4284 Pm=inf.

51. Economics Man-hours per week Structural Cost Break-Up Propulsion & Electronic Equipment Cost Total Cost of the project

52. Man-Hours

53. Structural Cost Cost = $ 292.00

54. Structural Cost Break-Up

55. Motor & Electronic Equipment

56. Total Cost Man-Hour Breakup Rate = $75/hour

57. Conclusions Flight performance requirements met Turn radius Endurance Take-off distance Stabilizing feedback implemented Future Work Data logger installation Implement destabilizing feedback Refine propulsion analysis method (further testing) Perfect construction method

58. Questions?