A model for the viscous dissipation rate in stably stratified, sheared turbulence

Autor:	Bjørn Anders Pettersson Reif, Hannibal E. Fossum, Emma M. M. Wingstedt
Rok vydání:	2013
Předmět:	Physics Turbulence K-epsilon turbulence model Isotropy Prandtl number Direct numerical simulation K-omega turbulence model Dissipation Physics::Fluid Dynamics symbols.namesake Geophysics symbols General Earth and Planetary Sciences Vector field Statistical physics
Zdroj:	Geophysical Research Letters. 40:3744-3749
ISSN:	0094-8276
Popis:	[1] A model for the turbulence dissipation rate in stably stratified shear turbulence is developed and validated. The functional dependence of the model is derived from first principles and it represents a conceptually new approach in that it depends on the background temperature field rather than on the fluctuating velocity field. This novel feature makes the proposed model a viable candidate for dissipation rate estimates in measured real-life flows. Direct numerical simulation data are used for a priori assessment of the proposed model. It is demonstrated that the proposed model performs very well, particularly in cases where the background stratification becomes dynamically important. Also, a generalized expression for the mixing coefficient has been rigorously derived from first principles assuming local isotropy of incompressible turbulent flows. The mixing coefficient is shown to depend on the Prandtl number and values are in correspondence with previous studies.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::755c1c00f4b9c77bc9f0195b60fb2533 https://doi.org/10.1002/grl.50663 Zobrazit plný text záznamu Plný text