An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 3 Search : mixing length
mixing length
  درازای ِ آمیزش   
derâzâ-ye âmizeš

Fr.: longueur de mélange   

In a → turbulent flow, the average distance traveled by a → convective cell before it dissolves into its surroundings and deposits its energy. The mixing length is of the order of the → pressure scale height (HP), l = αHP, where α is the → mixing length parameter. See also → mixing length theory.

mixing; → length.

mixing length parameter
  پارامون ِ درازای ِ آمیزش   
pârâmun-e derâzâ-ye âmizeš

Fr.: paramètre de la longueur de mémange   

In the → mixing length theory, a parameter, α, that relates the → mixing length, l, to the → pressure scale height: α = l/HP. It is usually supposed that α is of order unity. Changes in α correspond to variations in the efficiency of the → convection, hence the transfer of heat.

mixing; → length; → parameter.

mixing length theory (MLT)
  نگره‌ی ِ درازای ِ آمیزش   
negare-ye derâzâ-ye âmizeš

Fr.: théorie de la longueur de mélange   

A theory dealing with heat transport by → turbulence which includes an elementary treatment of → convection. The central idea is that an unbalanced → buoyancy force drives a → convective cell to move through a distance, called the → mixing length, before the cell dissolves and joins the ambient medium. In this theory an adjustable → mixing length parameter  α is used. The theory, originally due to L. Prandtl (1925), was first applied to the Sun by L. Biermann (1932, Z. Astrophys. 5, 117).

mixing; → length; → theory.