Modelling enhanced confinement in drift-wave turbulence

Autor:	R. J. Hajjar, Arash Ashourvan, Patrick Diamond, George Tynan
Rok vydání:	2017
Předmět:	Physics K-epsilon turbulence model Turbulence Wave turbulence Mechanics Vorticity Condensed Matter Physics Enstrophy 01 natural sciences 010305 fluids & plasmas Vortex Physics::Fluid Dynamics Classical mechanics Flow velocity 0103 physical sciences Turbulence kinetic energy 010306 general physics
Zdroj:	Physics of Plasmas. 24:062106
ISSN:	1089-7674 1070-664X
DOI:	10.1063/1.4985323
Popis:	The results of modeling studies of an enhanced confinement in the drift wave turbulent plasma of the CSDX linear device are presented. The mechanism of enhanced confinement is investigated here using a reduced 1D, time-dependent model, which illustrates the exchange of enstrophy between two disparate scale structures: the mesoscale flow and profile, and the turbulence intensity fields. Mean density, mean vorticity, and turbulent potential enstrophy are the variables for this model. Total potential enstrophy is conserved in this model. Vorticity mixing occurs on a scale length related to an effective Rhines' scale of turbulence, and shrinks as both density and vorticity gradients steepen. Numerical results obtained from solution of the model agree well with the experimental data from CSDX showing: (i) a steepening of the mean density profile, indicating a radial transport barrier formation, (ii) the development of a radially sheared azimuthal flow velocity that coincides with the density steepening and ini...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::8d28c9a5ef7bee3ae5c020bc46acf73a https://doi.org/10.1063/1.4985323 Zobrazit plný text záznamu