aerodynamics


aerodynamics
aerodynamic, aerodynamical, adj.aerodynamically, adv.
/air'oh duy nam"iks/, n. (used with a sing. v.)
the branch of mechanics that deals with the motion of air and other gases and with the effects of such motion on bodies in the medium. Cf. aerostatics (def. 1).
[1830-40; AERO- + DYNAMICS]

* * *

Branch of physics concerned with the forces acting on bodies passing through air and other gaseous fluids.

It explains the principles of flight of aircraft, rockets, and missiles. It is also involved in the design of automobiles, trains, and ships, and even stationary structures such as bridges and tall buildings, which must withstand high winds. Aerodynamics emerged as a discipline around the time of Wilbur and Orville Wright's first powered flight in 1903. Developments in the field have led to major advances in turbulence theory and supersonic flight.

* * *

      branch of physics that deals with the motion of air and other gaseous fluids and with the forces acting on bodies passing through such a fluid. Aerodynamics seeks, in particular, to explain the principles governing the flight of aircraft, rockets, and missiles. It is also concerned with the design of automobiles, high-speed trains, and ships, as well as with the construction of such structures as bridges and tall buildings to determine their resistance to high winds.

      Observations of the flight of birds and projectiles stirred speculation among the ancients as to the forces involved and the manner of their interaction. They, however, had no real knowledge of the physical properties of air, nor did they attempt a systematic study of those properties. Most of their ideas reflected a belief that the air provided a sustaining or impelling force. These notions were based to a large degree on the principles of hydrostatics (the study of the pressures of liquids) as they were then understood. Thus, in early times, it was thought that the impelling force of a projectile was associated with forces exerted on the base by the closure of the flow of air around the body. This conception of air as an assisting medium rather than a resisting force persisted for centuries, even though in the 16th century it was recognized that the energy of motion of a projectile was imparted to it by the catapulting device.

      Near the end of the 15th century, Leonardo da Vinci observed that air offered resistance to the movement of a solid object and attributed this resistance to compressibility effects. Galileo later established the fact of air resistance experimentally and arrived at the conclusion that the resistance was proportional to the velocity of the object passing through it. In the late 17th century, Christiaan Huygens (Huygens, Christiaan) and Sir Isaac Newton (Newton, Sir Isaac) determined that air resistance to the motion of a body was proportional to the square of the velocity.

      Newton's work in setting forth the laws of mechanics marked the beginning of the classical theories of aerodynamics. He considered the pressure acting on an inclined plate as arising from the impingement of particles on the side of the plate that faces the airstream. His formulation yielded the result that the pressure acting on the plate was proportional to the product of the density of the air, the area of the plate, the square of the velocity, and the square of the sine of the angle of inclination. This failed to account for the effects of the flow on the upper surface of the plate where low pressures exist and from which a major portion of the lift of a wing is produced. The idea of air as a continuum with a pressure field extending over great distances from the plate was to come much later.

      Various discoveries were made during the 18th and 19th centuries that contributed to a better understanding of the factors influencing the movement of solid bodies through air. The relationship of resistance to the viscous properties of a fluid, for example, was perceived in part by the early 1800s, and the experiments of the British physicist Osborne Reynolds in the 1880s brought into clearer view the significance of viscous effects.

      Modern aerodynamics emerged about the time that the Wright brothers made their first powered flight (1903). Several years after their historic effort, Frederick W. Lanchester (Lanchester, Frederick William), a British engineer, proposed a circulation theory of lift of an airfoil of infinite span and a vortex theory of the lift of a wing of finite span. The German physicist Ludwig Prandtl (Prandtl, Ludwig), commonly regarded as the father of modern aerodynamics, arrived independently at the same hypotheses as Lanchester and developed the mathematical treatment. Prandtl's work, refined and expanded by subsequent investigators, formed the theoretical foundation of the field. Among others who played a prominent role in the development of modern aerodynamics was the Hungarian-born engineer Theodore von Kármán, whose contributions led to major advances in such areas as turbulence theory and supersonic flight.

* * *


Universalium. 2010.

Look at other dictionaries:

  • Aerodynamics — is a branch of dynamics concerned with studying the motion of air, particularly when it interacts with a moving object. Aerodynamics is closely related to fluid dynamics and gas dynamics, with much theory shared between them. Aerodynamics is… …   Wikipedia

  • Aerodynamics — aer o*dy*nam ics Aerodynamics A [ e]r*o*dy*nam ics, n. [A[ e]ro + dynamics: cf. F. a[ e]rodynamique.] The science which treats of the air and other gaseous bodies under the action of force, and of their mechanical effects. [1913 Webster] …   The Collaborative International Dictionary of English

  • aerodynamics — (n.) 1837, from AERO (Cf. aero ) air + DYNAMICS (Cf. dynamics) …   Etymology dictionary

  • aerodynamics — [er΄ō dī nam′iks] n. the branch of aeromechanics that deals with the forces (resistance, pressure, etc.) exerted by air or other gases in motion pl.n. the characteristics of the outer body of a vehicle, aircraft, etc., that affect the efficiency… …   English World dictionary

  • aerodynamics — [[t]e͟əroʊdaɪnæ̱mɪks[/t]] N UNCOUNT (The form aerodynamic is used as a modifier. In British English, aerodynamics is sometimes used as a plural noun, with a plural verb.) Aerodynamics is the study of the way in which objects move through the air …   English dictionary

  • aerodynamics — i. The science that deals with the motion of air and other gaseous fluids and of the forces acting on bodies when the bodies move through such fluids, or when such fluids move against or around the bodies. It also studies the qualities required… …   Aviation dictionary

  • aerodynamics — /ˌɛəroʊdaɪˈnæmɪks / (say .airrohduy namiks) noun 1. the study of air in motion and of the forces acting on solids in motion relative to the air through which they move. Compare aerostatics (def. 1). 2. the properties of a solid object in relation …   Australian English dictionary

  • aerodynamics — aerodinamika statusas T sritis fizika atitikmenys: angl. aerodynamics vok. Aerodynamik, f rus. аэродинамика, f pranc. aérodynamique, f …   Fizikos terminų žodynas

  • aerodynamics — aerodinamika statusas T sritis Energetika apibrėžtis Aeromechanikos sritis, nagrinėjanti dujų (ir oro) judėjimą ir jėgas, veikiančias aptekamą kūną. Tai teorinis orlaivių, mentinių mašinų kūrimo pagrindas. Pagrindiniai šio mokslo klausimai yra… …   Aiškinamasis šiluminės ir branduolinės technikos terminų žodynas

  • aerodynamics — aerodinamika statusas T sritis Kūno kultūra ir sportas apibrėžtis Aeromechanikos dalis, tirianti oro terpės judėjimą ir pusiausvyrą, sąveiką su judančiais joje kietaisiais kūnais. Kaip mokslas susiformavo XX a. kilmė gr. aēro – oras + dynamikos – …   Sporto terminų žodynas


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.