Simulation of strongly stratified fluids
2008 (English)Conference paper (Refereed)
Stably and strongly stratified turbulent flows have been studied by employing scaling analysis of the governing equations along the lines of ,  and . The scaling analysis suggests the existence of two different dynamical states. The parameter determining the state is R = ReF h 2, 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 l v ∼ U/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 lv ∼ l hRe -1/2 (l h 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.
Place, publisher, year, edition, pages
2008. 373-378 p.
, Solid Mechanics and its Applications, ISSN 18753507
DNS, Geophysical flows, Stratification, Turbulence, Dynamical state, Forward energy, Governing equations, Horizontal velocity, Inertial forces, Length scale, Scaling analysis, Stratified fluid, Stratified turbulence, Viscous forces, Thermal stratification, Reynolds number
Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:kth:diva-153327DOI: 10.1007/978-1-4020-6472-2_56ISI: 000253667300056ScopusID: 2-s2.0-84861129123ISBN: 9781402064715OAI: oai:DiVA.org:kth-153327DiVA: diva2:755846
IUTAM Symposium on Computational Physics and New Perspectives in Turbulence; Nagoya; Japan; 11-14 September 2006
QC 201410152014-10-152014-10-032014-10-15Bibliographically approved