Gas dynamics (or gas dynamics ) is a branch of mechanics that studies the laws of motion of a gaseous medium and its interaction with solids moving in it. It is more often found under the name aerodynamics (from other Greek: ἀηρ - air and δύναμις - force), but includes not only aerodynamics, but also gas dynamics proper. The latter historically arose as a further development and generalization of aerodynamics, and that is why they often talk about a single science - aerodynamics. As part of physics, aerodynamics is closely related to thermodynamics and acoustics .
Aerodynamics
A section of hydroaeromechanics, in which the laws of air motion and forces arising on the surface of bodies relative to which its motion occurs are studied. In aerodynamics, traffic with subsonic speeds is considered, i.e., under normal conditions, up to 340 m / s (1200 km / h).
Applied aerodynamics problems:
- pressure distribution on the surface of the body;
- determination of forces and moments acting on a body streamlined by a gas;
- velocity distribution in the air stream flowing around the body;
- ventilation calculation;
- calculation of pneumatic transport .
A special section of aerodynamics - the aerodynamics of an airplane - is developing methods for aerodynamic calculation and determining the aerodynamic forces and moments acting on the airplane as a whole and its parts - wing , fuselage , plumage, etc. The aerodynamics of an airplane include: calculation of stability, balancing the airplane, propeller theory, wing theory. Issues related to the changing non-stationary mode of movement of aircraft are considered in a special section - flight dynamics .
The results of aerodynamics find numerous applications in aircraft construction , aircraft manufacturing , automotive and in various aircraft .
History of Aerodynamics
The founder of modern aerodynamics and aerohydrodynamics is considered the great Russian scientist Nikolai Egorovich Zhukovsky . [1] In 1902, he supervised the construction of a suction-type wind tunnel at the mechanical cabinet of Moscow University, in which an axial fan created air flow at a speed of up to 9 m / s. [2] In 1904, he headed the first aerodynamic institute in Europe, created with the funds of D. P. Ryabushinsky in the village of Kuchino near Moscow. In 1905, on November 15, Nikolai Yegorovich Zhukovsky gave a formula for calculating the lift, which is the basis of all aerodynamic calculations of the aircraft. [3] Since 1918 he headed TsAGI ( Central Aerohydrodynamic Institute ). [four]
Gas Dynamics
Gas dynamics arose as a further development of aerodynamics and deals with situations in which conditions differ significantly from normal .
Unlike classical aerodynamics, gas dynamics deals with such problems in which the compressibility of a gas becomes a significant factor influencing its behavior. First of all, these are problems on the motion of gas flows with velocities close to or greater than the speed of sound in a gas, which leads to the appearance of significant pressure drops and shock waves . Another example is those processes in gaseous media that accompany exothermic ( combustion , explosion ) or endothermic ( dissociation ) chemical reactions : in these cases, due to a change in the average molecular mass of the gas and energy release processes, the ideal gas model is not applicable.
The emergence of gas dynamics dates from the middle and second half of the 19th century and is associated with the fundamental works of K. Doppler , G. Riemann , E. Mach , W. J. Rankin and P.-A. Hugonio [5] . This section of mechanics is undergoing rapid development in the 20th century; Among the many names of scientists who have made a significant contribution to the development of gas dynamics, S. A. Chaplygin , J. Taylor , L. I. Sedov , and Y. B. Zel'dovich should be mentioned.
See also
- Supersonic speed
- Shock wave
- Geophysical hydrodynamics
- Aerodynamic Aircraft
- Car aerodynamics
Notes
- ↑ 5.N. Zhukovsky is the founder of aviation science. Nikolai Egorovich Zhukovsky - biography . StudFiles. Date of treatment February 16, 2019.
- ↑ Zhukovsky, Nikolai Egorovich .
- ↑ Nikolai Egorovich Zhukovsky (Russian) (neopr.) ? . Date of treatment February 16, 2019.
- ↑ Aerodynamics is ... Fundamentals and features of aerodynamics . FB.ru. Date of treatment February 16, 2019.
- ↑ Tyulina I.A. History and methodology of mechanics. - M .: Publishing house Mosk. University, 1979. - 282 p. - S. 235.
Literature
- Godunov S.K. , Zabrodin A.V., Ivanov M. Ya., Kraiko A.N. , Prokopov G.P. Numerical solution of multidimensional problems of gas dynamics. - M .: Nauka, 1976 .-- 400 p.
- Deutsch M. E. Technical gas dynamics. - M .: Energy, 1974.
- Deich M. E. , Filippov G. A. Gas dynamics of two-phase media. - M .: Energoatomizdat, 1981.
- Deich M.E. , Zaryankin A.E. Hydro-gasdynamics. - M .: Energoatomizdat, 1984.
- Kireev V.I., Voinovsky A.S. Numerical modeling of gas-dynamic flows. - M .: Publishing House of the Moscow Aviation Institute, 1991 .-- 254 p. - ISBN 5-7035-0148-2 .
- Kraiko A.N. Variational problems of gas dynamics. - M .: Nauka, 1979.- 447 p.
- Mises R. Mathematical theory of compressible fluid flows. - M .: IIL, 1961 .-- 588 p.
- Sow S. Hydrodynamics of multiphase media. - M .: Mir, 1971.
- Falkovich, G. Fluid Mechanics, a short course for physicists . - Cambridge University Press, 2011 .-- ISBN 978-1-107-00575-4 .
Links
- Aerodynamics // Brockhaus and Efron Encyclopedic Dictionary : in 86 volumes (82 volumes and 4 additional). - SPb. , 1890-1907.
- Modern problems of aerophysics
- "Aerodynamics" Lecture by Yuri Ryzhov from the cycle ACADEMIA (video)
- A site dedicated to fluid dynamics with videos, questions, etc.
- Educational film "General laws of aerodynamics"