Engineering Science

Engineering Science

Science leads to applied science leads to technology--NOT SO (or not always)

What are the possible relationships between science and technology:

new scientific discovery provides the basis for a new technology
use scientific information or research to improve an existing product
new science can grow out of trying to understand existing technology
scientists develop instruments for scientific research that turn out to be useful for other things
engineers can use the scientific method and do their own research (engineering science)

Physics couldn't tell you anything useful about aerodynamics until after World War II. Therefore aviation is a good example of the complex ways in which engineers use science.

Engineering science = "scientific" theories developed by engineers for engineers

Systematically vary the relevant parameters and learn the relationships (eg. between wind shape and lift). Represent the results as a mathematical relationship or as a table of data

The invention of the airplane:

Flight had been a dream for a long time, but generally by direct analogy to birds and therefore with flapping wings (Leonardo). Balloons came into use in the late 18th century and saw significant use in the Civil War and for sport, so there was some familiarity with the atmosphere as an environment.
By the end of the 1800s gliders had been flown successfully and a number of people were working on powered gliders.
The Smithsonian Institution's head, Samuel Pierpont Langley, had a government grant to build a heavier-than-air craft. His approach was to "urge a system of rigid planes through the air at great velocity" in other words like running a knife through butter. He visualized air as a series of identical elastic cubes.

Langley Aerodome--National Air and Space Museum

He tested one design before the Wright brothers, but couldn't get off the ground. But he owned the Washington establishment--nobody paid any attention to the Wright Brothers.
the Wright brothers emphasized the fluid nature of air, and sought a plane that was flexible and adjustable, not rigid.
Now mind you, they were not scientists, but they were bicycle-makers and racers who read the professional literature, studied the problems of aviation with great care and corresponded with other aeronautical researchers such as Octave Chanute. The Wright brothers even built their own wind tunnel--6 feet long and 16 inches square to study the relationship of various wing shapes and lift and also propellers. Some of the other researchers were professional engineers and scientists, but the Wrights could do just as good empirical research.
they developed a system to turn the plane with a rudder linked to a system to warping the entire wing so that the plane would bank in flight, tested it extensively in gliders. They built their own gasoline engine, because they could not find a suitable one on the market, and a much more efficient propeller. They successfully flew a powered airplane Dec. 17, 1903 (for more on the Wright Brothers and their process of invention--and lots of pictures and quick-time movies--see To Fly is Everythingand to listen to a story about their forgotten sister go to: NPR audio story and click listen)

Wright Brothers flight, National Air and Space Museum

the Wright brothers had a terrible time interesting anyone in their success--the U.S. military did not purchase its first plane until 1909

Europeans were more interested, and during World War I learned to use aircraft for reconnaissance, bombing, and fighting
when the U.S. entered World War I in 1917, we lagged far behind in military aircraft
In the year before the U.S. declared war the U.S. aviation industry produced 411 planes, though a large number of airplane engines were shipped to Europe by one company partnership that had designed a good lightweight engine and techniques for mass-producing it (the Liberty Engine, Packard and Hall-Scott).
by the end of the war in 1919 the army had 5,500 planes, though most of the fighters were purchased in Europe. The U.S. industry did successfully produce trainers, and many planes were in production when the war ended

French Spad WWI fighter--National Air and Space Museum

there was a need for research also, or at least coordination, and it almost instantly outgrew the resources of amateurs like the Wright brothers or even the small firms that were building aircraft.

The National Advisory Committee on Aeronautics was one of a number of organizations created as a result of lobbying by scientists and engineers for a new government role in research and development in World War I.
President Wilson signed the naval appropriations bill that created the National Advisory Committee on Aeronautics in March 1915. The scientists, engineers and enthusiasts who had lobbied for the bill for more than four years wanted government funding of aeronautical research to allow the United States to catch up with rapid developments in Europe. But the legislation did not pass until the outbreak of war provided an additional push, and the bill did nothing more than create an advisory committee and provide it with a small appropriation.

The NACA then set out to invent its own role. In its first few years the new Committee played a significant role in the wartime coordination of industry and used some of its small budget to sponsor research at private institutions, but its leaders made the building of a new laboratory their highest priority. The laboratory at Langley Field, in Virginia, established the NACA as a federal research agency despite its title as an advisory committee. After the war ended, debates over the role of the federal government in supporting and regulating aviation created considerable uncertainly about the future of the NACA, but the final result strengthened the Committee's emphasis on research because other aviation-related functions--regulation and the sponsorship of infrastructure--were assigned to the Department of Commerce. The federal government also helped the aviation industry by funding air mail service.
At the Langley Memorial Laboratory, dedicated in June 1920, NACA scientists and engineers set out to invent a role for the federal government in peacetime aviation research. The laboratory provided fairly up-to-date facilities: a wind tunnel, an engine-dynamometer laboratory, and a general research laboratory building.
The laboratory developed a focus on aeronautical principles both in order to take advantage of its wind tunnel facilities and to avoid competition with the military services (which wanted to maintain control of testing and setting specifications for new aircraft designs for military missions) and the National Bureau of Standards and industry (which had facilities for engine research).
The NACA found a niche not only in its choice of research program but also in how it approached research problems: "The strength of the NACA seems to be that it had the luxury of pursuing incrementally over a long period of time answers to problems that were of great interest to the commercial and military worlds."
The leaders of the NACA initially thought that the committee had to establish its reputation by scientific (not engineering) achievement, and hired Max Munk from Germany because of his theoretical reputation. Munk made a key discovery, that by compressing the air in a tunnel you could use scale models in wind tunnels to provide results that would correlate with data from a full-sized plane in actual use. This idea was put into use in a 5 foot diameter variable density tunnel in 1923, and then was followed by a 20 foot diameter tunnel for full scale research in 1927.

NACA's first wind tunnel

the NACA used the large tunnel for research on propellers, landing gear, and drag. They discovered that the engine provide as much as 1/3 of the plane's total drag, and invented a way to cover the engine to enhance cooling while reducing drag. During a test a plane that normally averaged 157 mph averaged 177 mph. But this wasn't a theoretical breakthrough--each cowling was custom developed for a particular combination of airplane and engine by wind tunnel experiments.

detail from Diego Rivera mural at Detroit Institute of Art

The necessity of practical results to justify federal funding and the dominant role of engineers on the NACA main committee gradually reversed that attitude, establishing the relationship between theoretical and practical research as a central tension within the laboratory and the agency as a whole.

Development of Aeronautical Engineering:

Expertise spread: in 1929 1400 students were studying aero-engineering in more than a dozen schools.
Meanwhile, aircraft design was developing in the 1920s and 1930s as the market finally began to expand again.
Ford trimotor of 1926--metal structure and cantilevered wing.

Ford Trimotor, National Air and Space Museum

People began to predict that soon there would be an airplane in every garage
Aluminum propeller developed in 1925, and variable pitch propellers by the end of the decade.
The first successful helicopter flew in Germany in 1936; Russian emigre Igor Sikorsky had a U.S. design in tests by 1939 and got a contract from the army in 1940

Sikorsky's first helicopter

research became more complex.

As aviation technology became more complex in the late interwar period, the NACA found itself sponsoring not only research on components and design parameters but large-scale research and development projects.
World War II brought a return to more practical concerns, but with the greater emphasis on government-funded technology characteristic of the war years it also provided the NACA with broader experience in large development programs and some push to take bigger risks.
Perhaps most notably, members of the aviation community saw supersonic flight as the next step, but making that step required both theoretical research, wind tunnel testing, and actual building of experimental aircraft. Those experimental aircraft were no longer prototypes of new military aircraft, but now were designed solely for research purposes.
The NACA therefore found itself in the business of contracting with industry for the design and manufacture of radically new vehicles. The X-15 project supersonic test vehicle project in particular differed little in scale and scope from space projects of a few years later.

X-15--National Air and Space Museum

Engineering science is systematic experimentation aimed at seeing the overall patterns, not just solving specific practical problems. It may be simply empirical work, but it aims at describing patterns, hopefully in equations.

this page written and copyright Pamela E. Mack
History 122
last updated 10/12/2005