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

CapstoneCapstone

1

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

Alan Parkinson

ME 475 Capstone

CapstoneCapstone

2

Wilbur and Orville

Wilbur, 1880, age 13 Orville, 1880, age 9

CapstoneCapstone

3

Early Ventures

CapstoneCapstone

4

Bishop Milton Wright

Church of the United Brethren in

Christ

CapstoneCapstone

5

Bicycle Shop

CapstoneCapstone

6

Bicycle Shop, 1897

Ed Sines and Orville Wright

CapstoneCapstone

7

Pioneers in Flight

Otto Lilienthal

1848-1896

CapstoneCapstone

8

Lilienthal’s Glider

CapstoneCapstone

9

Pioneers in Flight

Octave Chanute

1832-1910

CapstoneCapstone

10

Pioneers in Flight

Samuel Langley

1834-1906

CapstoneCapstone

11

Gathering Information

CapstoneCapstone

12

Data for 1899 Experiments

CapstoneCapstone

13

Information Gathering

CapstoneCapstone

14

Wing Warping

CapstoneCapstone

15

First Camp, Kitty Hawk, 1900

CapstoneCapstone

16

1900 Glider

CapstoneCapstone

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)

CapstoneCapstone

18

1900 Glider

CapstoneCapstone

19

1901 Camp

CapstoneCapstone

20

1901 Glider

CapstoneCapstone

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)

CapstoneCapstone

22

CapstoneCapstone

23

CapstoneCapstone

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

CapstoneCapstone

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)

CapstoneCapstone

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.

CapstoneCapstone

27

Bicycle Experiment

CapstoneCapstone

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

CapstoneCapstone

29

Wind Tunnel

CapstoneCapstone

30

Lift Balance

CapstoneCapstone

31

Drift Balance

CapstoneCapstone

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)

CapstoneCapstone

33

Lift Calculations

CapstoneCapstone

34

CapstoneCapstone

35

CapstoneCapstone

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)

CapstoneCapstone

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)

CapstoneCapstone

38

Camp 1902

CapstoneCapstone

39

Camp 1902

CapstoneCapstone

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)

CapstoneCapstone

41

1902 vs. 1901 Glider

CapstoneCapstone

42

1902 Glider

CapstoneCapstone

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)

CapstoneCapstone

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)

CapstoneCapstone

45

Gliding Oct 10, 1902

CapstoneCapstone

46

Gliding Oct 24, 1902

CapstoneCapstone

47

Wing Warping

CapstoneCapstone

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)

CapstoneCapstone

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

CapstoneCapstone

50

Engine

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

CapstoneCapstone

51

Engine Development

“The first thing we did was to construct a sort of skeleton model, a test cylinder of about a four inch bore. The Wright boys were thorough that way. They wanted to see how some of the vital components worked before proceeding further. We hooked the test cylinder up to the shop power, smeared it with oil with a paint brush, and watched it run for short periods. It looked good; so we decided to go ahead with a four cylinder model.”

Charles Taylor, mechanic who worked for Wright brothers

CapstoneCapstone

52

Engine Development

Obviously much forethought and careful design work preceded actual construction. There are no haphazard or “cobbled up” solutions. The intricate crankcase casting, for instance, shows evidence of much forethought on the overall engine design providing for webs, brackets, bosses, and contours to hold and support other engine parts. The records indicate that the Wrights made their own wood casting patterns. (Lippincott, p. 82)

CapstoneCapstone

53

Engine,12-16 hp, 180 lbs

CapstoneCapstone

54

CapstoneCapstone

55

Engine Development

The fact that the Wrights, with no prior experience with any type of internal combustion engine, were able to design and build a successful engine that was beyond the state-of-the-art, and to accomplish this in the space of six months, is truly amazing. (Anderson, p. 16)

CapstoneCapstone

56

1910 Engine

CapstoneCapstone

57

Propeller Theory

“What at first seemed a simple problem became more complex the longer we studied it. With the machine moving forward, the air flying backward, the propellers turning sidewise, and nothing standing still, it seemed impossible to find a starting point from which to trace the various simultaneous reactions. Contemplation of it was confusing. After long arguments we often found ourselves in the ludicrous position of each having been converted to the other’s side with no more agreement than when the discussion began.”

CapstoneCapstone

58

Propellers

CapstoneCapstone

59

Propeller Theory

The Wright propellers, designed according to their own calculations, were the first propellers ever built by anyone for which the performance could be predicted. After tests, their propellers produced not quite 1 percent less thrust than they had calculated. In useful work they gave about two thirds of the power expended-a third more than had been achieved by…Maxim and Langley. (East, p. 35)

CapstoneCapstone

60

It all comes together!

CapstoneCapstone

61

CapstoneCapstone

62

CapstoneCapstone

63

CapstoneCapstone

64

CapstoneCapstone

65

Langley Attempt 7 October 1903

CapstoneCapstone

66

Langley Attempt

A man forward fired two skyrockets…A mechanic stooped, cut the cable holding the catapult; there was a roaring, grinding noise-and the Langley airship tumbled over the edge of the houseboat and disappeared in the river, sixteen feet below. It simply slid into the water like a handful of mortar….(from a newspaper account)

CapstoneCapstone

67

Langley Attempt

“if it is to cost us $73,000 to construct a mud duck that will not fly 50 feet, how much is it going to cost to construct a real flying machine?”

James Hemenway, chairman of the House Appropriations committee

“We are still far from the ultimate goal, and it would seem as if years of constant work and study by experts, together with the expenditure of thousands of dollars, would still be necessary before we can hope to produce an apparatus of practical utility…”

From the War dept. report of Langley flight

CapstoneCapstone

68

Kitty HawkNov,1903

CapstoneCapstone

69

Flyer, First AttemptDec 14, 1903

CapstoneCapstone

70

Minor Damage

CapstoneCapstone

71

Witnesses and Helpers

CapstoneCapstone

72

Dec 17, 1903

CapstoneCapstone

73

Third Flight, Dec 17

CapstoneCapstone

74

Fourth Flight

CapstoneCapstone

75

Huffman Field, Dayton Ohio, 1904

CapstoneCapstone

76

Huffman Field, Dayton Ohio, 1904

CapstoneCapstone

77

1905 Flight, 20.8 miles in 33.3 minutes

CapstoneCapstone

78

Catapult

CapstoneCapstone

79

Wilbur circa 1908 1867-1912

Orville circa 1908 1871-1948

CapstoneCapstone

80

Final Thoughts

“After these years of experience, I look with amazement upon our audacity in attempting flights with a new and untried machine under such circumstances. Yet faith in our calculations and the design of the first machine, based upon our tables of air pressures, obtained by months of careful laboratory work and confidence in our system of control developed by three years of actual experiences in balancing gliders in the air, had convinced us that the machine was capable of lifting and maintaining itself in the air, and that, with a little practice, it could safely be flown.”

Orville Wright, commenting upon the first powered flight

CapstoneCapstone

81

Telegram Home

CapstoneCapstone

82

What helped them be successful?