TITLE

Energetic study of the transition to nonlinear state in two-dimensional electron temperature gradient fluid turbulence

AUTHOR(S)
Kim, J.-H.; Terry, P. W.
PUB. DATE
November 2010
SOURCE
Physics of Plasmas;Nov2010, Vol. 17 Issue 11, p112306
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Eigenmode projection has been used in analysis of the two-dimensional numerical solution of electron temperature gradient (ETG) turbulence. The secondary Kelvin-Helmholtz instability (KHI) that breaks up the primary ETG structure at the onset of saturation is found to be associated with strong excitation of damped eigenmodes and strong energy damping. While the KHI structure induces some fine scale motions, which can be dissipated by collisional damping, the structure also damps directly at low poloidal wavenumbers through stable eigenmodes. The latter process is persistent in time, while the former occurs only transiently at the initial breakdown of the linearly dominant ETG structure. The persistence of energy damping by stable eigenmodes during and after the transition is enabled by nonlinear advection of electron pressure. Thus, KHI in this system couples with electron pressure advection to generate a dissipative structure at low poloidal wavenumber.
ACCESSION #
55509489

 

Related Articles

  • Damped eigenmode saturation in plasma fluid turbulence. Makwana, K. D.; Terry, P. W.; Kim, J.-H.; Hatch, D. R. // Physics of Plasmas;Jan2011, Vol. 18 Issue 1, p012302 

    A broad sample of fluid models for instability-driven plasma turbulence is surveyed to determine whether saturation involving damped eigenmodes requires special physics or is a common property of plasma turbulence driven by instability. Previous investigations have focused exclusively on...

  • Role of stable modes in zonal flow regulated turbulence. Makwana, K. D.; Terry, P. W.; Kim, J.-H. // Physics of Plasmas;Jun2012, Vol. 19 Issue 6, p062310 

    Zonal flows are shown to regulate ion temperature gradient turbulence by enabling efficient energy transfer from the instability to a damped eigenmode in the unstable wavenumber range. The damped mode also saturates turbulence when zonal flows are not active in saturation dynamics, for example,...

  • Structure of micro-instabilities in tokamak plasmas: Stiff transport or plasma eruptions? Dickinson, D.; Roach, C. M.; Skipp, J. M.; Wilson, H. R. // Physics of Plasmas;Jan2014, Vol. 21 Issue 1, p1 

    Solutions to a model 2D eigenmode equation describing micro-instabilities in tokamak plasmas are presented that demonstrate a sensitivity of the mode structure and stability to plasma profiles. In narrow regions of parameter space, with special plasma profiles, a maximally unstable mode is found...

  • Conditional sampling of dissipation in moderate Reynolds number grid turbulence. Thoroddsen, S.T. // Physics of Fluids;May96, Vol. 8 Issue 5, p1333 

    Describes the use of multi-point hot-wire measurements in grid turbulence to conditionally average the dissipation over inertial-scale features of the turbulent field. Approximation of the dissipation with pseudo- or surrogate dissipation; Conditional averaging over strong large-scale fronts...

  • (1+1)-dimensional turbulence. Benzi, R.; Biferale, L.; Tripiccione, R.; Trovatore, E. // Physics of Fluids;Aug97, Vol. 9 Issue 8, p2355 

    Studies a class of dynamical models of turbulence living on a one-dimensional dyadic-tree structure. Natural generalization of the popular GOY shell model of turbulence; Energy dissipation statistics; Confirmation of the refined Kolmogorov hypothesis.

  • Direct, high resolution, four-dimensional measurements of the fine scale structure of Sc>1 molecular mixing in turbulent flows. Dahm, Werner J. A.; Southerland, Kenneth B.; Buch, Kenneth A. // Physics of Fluids A;May91, Vol. 3 Issue 5, p1115 

    Results from highly resolved, four-dimensional measurements of the fine structure of the fully space- and time-varying Sc » 1 conserved scalar field and the associated scalar energy dissipation rate field in a turbulent flow are presented. The resolution achieved in all three spatial...

  • The self-preserving decay of isotropic turbulence: Analytic solutions for energy and dissipation. Ristorcelli, J.R. // Physics of Fluids;Oct2003, Vol. 15 Issue 10, p3248 

    Analytic solutions for the nonlinear single-point equations, describing the isotropic decay of turbulence, as first formulated by von Kármán and Howarth [Proc. R. Soc. London, Ser. A 164, 192 (1938)] are given. The asymptotic solution indicates the self-preserving k(t)∼t[sup -1]...

  • Experimental assessment of Taylor's hypothesis and its applicability to dissipation estimates in... Dahm, Werner J.A.; Southerland, Kenneth B. // Physics of Fluids;Jul97, Vol. 9 Issue 7, p2101 

    Assesses the applicability of Taylor's hypothesis for approximating streamwise derivatives and obtaining dissipation estimates in turbulent flows. Fully resolved measurements of a conserved scalar field throughout a four-dimensional spatio-temporal volume in a turbulent flow; Measurement technique.

  • Some remarks concerning recent work on rotating turbulence. Zhou, Ye; Speziale, Charles G. // Physics of Fluids;Dec98, Vol. 10 Issue 12, p3242 

    Comments on the article 'A dynamical model of turbulence,' by V.M. Canuto and M.S. Dubovikov, which appeared in the journal 'Physics of Fluids.' Objection to the authors' claim that they have discovered a new energy spectrum scaling law for rotating turbulence; Consistency of the spectral...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics