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Simulation of Strongly Stratified Fluids

  • G. Brethouwer
  • P. Billant
  • E. Lindborg
Conference paper
Part of the IUTAM Bookseries book series (IUTAMBOOK, volume 4)

Abstract

Stably and strongly stratified turbulent flows have been studied by employing scaling analysis of the governing equations along the lines of [1], [2] and [3]. The scaling analysis suggests the existence of two different dynamical states. The parameter determining the state is R = ReF h2, where Re and Fh are the Reynolds number and horizontal Froude number, respectively. If R ≫ 1, viscous forces are negligible and the turbulence is strongly anisotropic but three-dimensional and causes a forward energy cascade. The vertical length scale lv scales as lvU/N (U is a horizontal velocity scale and N is the Brunt-Väisälä frequency). If R ≪ 1, horizontal inertial forces are balanced by vertical viscous shearing and lvlhRe-1/2 (lh is a horizontal length scale). The scaling analysis has been confirmed by direct numerical simulations of homogeneous stratified turbulence. Spectra have been studied as well.

Keywords

stratification DNS turbulence geophysical flows 

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References

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Copyright information

© Springer 2008

Authors and Affiliations

  • G. Brethouwer
    • 1
  • P. Billant
    • 2
  • E. Lindborg
    • 1
  1. 1.Department of MechanicsKTHStockholmSweden
  2. 2.Ecole PolytechniqueLadHyXPalaiseau CedexFrance

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