Pioneers in Flight: The Wright Brothers as a Case Study of Engineering Design

1. Pioneers in Flight:The Wright Brothers as a Case Study of Engineering Design Alan Parkinson ME 475 Capstone

2. Wilbur and Orville Orville, 1880, age 9 Wilbur, 1880, age 13

3. Early Ventures

4. Bishop Milton Wright Church of the United Brethren in Christ

5. Bicycle Shop

6. Bicycle Shop, 1897 Ed Sines and Orville Wright

7. Pioneers in Flight Otto Lilienthal 1848-1896

8. Lilienthal’s Glider

9. Pioneers in Flight Octave Chanute 1832-1910

10. Pioneers in Flight Samuel Langley 1834-1906

11. Gathering Information

12. Data for 1899 Experiments

13. Information Gathering

14. Wing Warping

15. First Camp, Kitty Hawk, 1900

16. 1900 Glider

17. 1900 Glider Almost as soon as they began their trials—they got a surprise. According to the Lilienthal tables of air pressures, their machine of 165 square feet needed a wind of seventeen to twenty-one miles an hour to support it as a kite with a pilot aboard. But they found that much stronger winds were needed to lift it…(Kelly, p.37)

18. 1900 Glider

19. 1901 Camp

20. 1901 Glider

21. 1901 Glider Although several flights on this first day of experiments in 1901 exceeded the best made the year before, yet it was soon evident that in several respects the machine was not as good as the first one. It was found that the wings, with a camber of one to twelve-the camber recommended by Lilienthal, and used by Chanute and others-was not so good as the camber of one to twenty two, used by the Wrights in 1900. (Kelly, p.40)

24. Striking Out on Their Own “having set out with absolute faith in the existing scientific data, we were driven to doubt one thing after another, until finally, after two years of experiment, we cast it all aside, and decided to rely entirely upon our own investigations.” Wilbur Wright

25. Design Method With little money to spend on a hobby, it was much cheaper to rectify mistakes on paper than after the idea was put into material form. They knew that if they should decide to go on to further gliding attempts, they could not afford to spend much more money on apparatus built according to unreliable data. (Kelly, p.46)

26. Bicycle Experiment • The Wrights built a device to check Lilienthal’s data. The device consisted of a bicycle wheel, with a flat plate on one side and an airfoil on the other, mounted horizontally to the handlebars of a regular bicycle. • If Lilienthal’s data were wrong, the horizontal wheel would rotate counter-clockwise.

27. Bicycle Experiment

28. Bicycle Experiment More attempts brought the same result…They had suspected something was wrong in Lilienthal’s tables. The wheel proved it. Still, it was a pretty crude experiment. It had to be checked. With gathering excitement, they tore the ends off a discarded wooden starch box and fitted a fan to one of the open ends. This made a little wind tunnel of the sort they had encountered in their readings. Tobin pg. 124

29. Wind Tunnel

30. Lift Balance

31. Drift Balance

32. Wind Tunnel Experiments In a period of about two months toward the close of 1901, the Wrights tested more than 200 surfaces. They measured monoplane, biplane, and triplane wing models….They measured lift and drag forces at various angles from 2 degrees to 45 degrees, tangentials, gliding angles, and lift/drag ratios; they tested the effect of aspect ratio and the effect on lift of varying the camber of curvature of the surfaces, and tried a variety of shapes and thicknesses for the leading and trailing edges, for wingtips, and for such structural members as uprights. (East, p. 27)

33. Lift Calculations

36. Wind Tunnel Experiments As a result of these experiments, all carefully carried out and minutely recorded, they obtained a body of data on air pressures and on the aerodynamic properties of wings, control surfaces, and structural parts. The extent and reliability of the information from these tests far exceeded anything that had ever been available to other experimenters or was to be available for at least another decade. Their friend and correspondent, Octave Chanute, marveled at the speed and accuracy with which this laboratory research was carried out. (East p.27)

37. Focus “They didn’t put themselves out to get acquainted with anybody,’ said John Daniels, one of the regulars at the lifesaving station. ‘Just stuck to themselves, and we had to get acquainted with them. They were two of the workingest boys I ever saw, and when they worked they worked. I never saw men so wrapped up in their work in my life. They had their whole heart and soul in what they were doing, and when they were working we could come around and stand right over them and they wouldn’t pay any more attention to us than if we weren’t there at all. After their day’s work was over they were different; then they were the nicest fellows you ever saw and treated us fine.” (Tobin, pg. 145)

38. Camp 1902

39. Camp 1902

40. 1902 Glider Because of the knowledge they now had, not possessed by any previous experimenter, of how the wings should be shaped, this 1902 machine was just about twice the “dynamic efficiency” of any other glider ever built; it could have been flown with probably less than half the power required of any other glider. (Kelly p. 47)

41. 1902 vs. 1901 Glider

42. 1902 Glider

43. 1902 Glider Altogether the Wrights made more than one thousand gliding flights in September and October 1902. Several glides were of more that six hundred feet, and a number of them were against a thirty-six-mile-an-hour wind. No previous experimenter had ever dared to try gliding in so stiff a wind. (Kelly)

44. Control We have used recent wind tunnel data and modern theory of stability and control to confirm the Wrights’ unparalleled understanding of aircraft control. Solution of the problem of turning was their supreme achievement in flight dynamics….Their success required appreciation of aerodynamics and invention of a simple means for the pilot to exercise lateral control with coordinated wing warping and rudder deflection. (Culick and Jex, p. 41)

45. Gliding Oct 10, 1902

46. Gliding Oct 24, 1902

47. Wing Warping

48. Approach “Their long glides had grown out of their particular aptitude for learning how to do a difficult thing. It was a simple method but rare. They broke a job into its parts and proceeded one part at a time. They practiced each small task until they mastered it, then moved on. It didn’t sound like much, but it avoided discouragement and led to success. And it kept them uninjured and alive.” (Tobin, pg. 156)

49. Next Step: Powered Flight • Wrights could: • Predict the performance of a glider design • Based on theory validated with experimental data • Build high performance gliders • Control a glider in flight in all three axes • Problems remaining: • Obtain an engine with adequate power • Design and build propellers to create thrust • Integrate into a complete airplane

50. Engine • Based on calculations for a powered1903 model, they needed an engine • capable of producing 9 hp • weighing no more than 180 pounds