30 research outputs found
The Microstructure of Turbulent Flow
In 1941 a general theory of locally isotropic turbulence was proposed by Kolmogoroff which permitted the prediction of a number of laws of turbulent flow for large Reynolds numbers. The most important of these laws, the dependence of the mean square of the difference in velocities at two points on their distance and the dependence of the coefficient of turbulence diffusion on the scale of the phenomenon, were obtained by both Kolmogoroff and Obukhoff in the same year. At the present time these laws have been experimentally confirmed by direct measurements carried out in aerodynamic wind tunnels in the laboratory, in the atmosphere, and also on the ocean. In recent years in the Laboratory of Atmospheric Turbulence of the Geophysics Institute of the Soviet Academy of Sciences, a number of investigations have been conducted in which this theory was further developed. The results of several of these investigations are presented
Radio scintillation of gamma-ray-burst afterglows
Stars twinkle to the eye through atmospheric turbulence, but planets, because
of their larger angular size, do not. Similarly, scintillation due to the local
interstellar medium will modulate the radio flux of gamma-ray-burst afterglows
and may permit indirect measurements of their angular sizes. The amplitude of
refractive scintillation is of order ten percent at ten gigahertz unless the
source size is much larger than the expected size, of order ten
microarcseconds. Diffractive scintillation is marginally possible, depending
sensitively on the source size, observing frequency, and scattering measure of
the interstellar medium.Comment: 11 pages, LaTeX2e, requires elsart.cls. Submitted to New Astronom
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Mikrostructura turbulentnogo potoka
"In 1941 a general theory of locally isotropic turbulence was proposed by Kolmogoroff which permitted the prediction of a number of laws of turbulent flow for large Reynolds numbers. The most important of these laws, the dependence of the mean square of the difference in velocities at two points on their distance and the dependence of the coefficient of turbulence diffusion on the scale of the phenomenon, were obtained by both Kolmogoroff and Obukhoff in the same year. At the present time these laws have been experimentally confirmed by direct measurements carried out in aerodynamic wind tunnels in the laboratory, in the atmosphere, and also on the ocean" (p. 1)
