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Non-isotropic dissipation in non-homogeneous turbulence

Oberlack, Martin :
Non-isotropic dissipation in non-homogeneous turbulence.
[Online-Edition: http://journals.cambridge.org/action/displayAbstract?fromPag...]
In: Journal of Fluid Mechanics, 350 pp. 351-374. ISSN 0022-1120
[Article] , (1997)

Official URL: http://journals.cambridge.org/action/displayAbstract?fromPag...

Abstract

On the basis of the two-point velocity correlation equation a new tensor length-scale equation and in turn a dissipation rate tensor equation and the pressure strain correlation are derived by means of asymptotic analysis and frame-invariance considerations. The new dissipation rate tensor equation can account for non-isotropy effects of the dissipation rate and streamline curvature. The entire analysis is valid for incompressible as well as for compressible turbulence in the limit of small Mach numbers. The pressure strain correlation is expressed as a functional of the two-point correlation, leading to an extended compressible version of the linear formulation of the pressure strain correlation. In this turbulence modelling approach the only terms which still need ad hoc closure assumptions are the triple correlation of the fluctuating velocities and a tensor relation between the length scale and the dissipation rate tensor. Hence, a consistent formulation of the return term in the pressure strain correlation and the dissipation tensor equation is achieved. The model has been integrated numerically for several different homogeneous and inhomogeneous test cases and results are compared with DNS, LES and experimental data.

Item Type: Article
Erschienen: 1997
Creators: Oberlack, Martin
Title: Non-isotropic dissipation in non-homogeneous turbulence
Language: English
Abstract:

On the basis of the two-point velocity correlation equation a new tensor length-scale equation and in turn a dissipation rate tensor equation and the pressure strain correlation are derived by means of asymptotic analysis and frame-invariance considerations. The new dissipation rate tensor equation can account for non-isotropy effects of the dissipation rate and streamline curvature. The entire analysis is valid for incompressible as well as for compressible turbulence in the limit of small Mach numbers. The pressure strain correlation is expressed as a functional of the two-point correlation, leading to an extended compressible version of the linear formulation of the pressure strain correlation. In this turbulence modelling approach the only terms which still need ad hoc closure assumptions are the triple correlation of the fluctuating velocities and a tensor relation between the length scale and the dissipation rate tensor. Hence, a consistent formulation of the return term in the pressure strain correlation and the dissipation tensor equation is achieved. The model has been integrated numerically for several different homogeneous and inhomogeneous test cases and results are compared with DNS, LES and experimental data.

Journal or Publication Title: Journal of Fluid Mechanics
Volume: 350
Publisher: Cambridge Journals Online
Divisions: 16 Department of Mechanical Engineering > Fluid Dynamics (fdy)
16 Department of Mechanical Engineering
Date Deposited: 23 Aug 2011 14:48
Official URL: http://journals.cambridge.org/action/displayAbstract?fromPag...
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