The dynamics of interacting nonlinearities governing long wavelength driftwave turbulence
Abstract
Because of the ubiquitous nature of turbulence and the vast array of different systems which have turbulent solutions, the study of turbulence is an area of active research. Much present day understanding of turbulence is rooted in the well established properties of homogeneous NavierStokes turbulence, which, due to its relative simplicity, allows for approximate analytic solutions. This work examines a group of turbulent systems with marked differences from NavierStokes turbulence, and attempts to quantify some of their properties. This group of systems represents a variety of drift wave fluctuations believed to be of fundamental importance in laboratory fusion devices. From extensive simulation of simple local fluid models of long wavelength drift wave turbulence in tokamaks, a reasonably complete picture of the basic properties of spectral transfer and saturation has emerged. These studies indicate that many conventional notions concerning directions of cascades, locality and isotropy of transfer, frequencies of fluctuations, and stationarity of saturation are not valid for moderate to long wavelengths. In particular, spectral energy transfer at long wavelengths is dominated by the E x B nonlinearity, which carries energy to short scale in a manner that is highly nonlocal and anisotropic. In marked contrast to the canonical selfsimilar cascademore »
 Authors:

 Univ. of Wisconsin, Madison, WI (United States)
 Publication Date:
 Research Org.:
 Wisconsin Univ., Madison, WI (United States). Plasma Physics Research
 Sponsoring Org.:
 USDOE
 OSTI Identifier:
 10103225
 Report Number(s):
 DOE/ER/53291225
ON: DE94001785; BR: AT0520210; TRN: 94:001335
 DOE Contract Number:
 FG0289ER53291
 Resource Type:
 Thesis/Dissertation
 Resource Relation:
 Other Information: TH: Thesis (Ph.D.); PBD: Sep 1993
 Country of Publication:
 United States
 Language:
 English
 Subject:
 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; TURBULENCE; NONLINEAR PROBLEMS; PLASMA DRIFT; NAVIERSTOKES EQUATIONS; MAGNETIC CONFINEMENT; PLASMA WAVES; 700340; 700330; PLASMA WAVES, OSCILLATIONS, AND INSTABILITIES; PLASMA KINETICS, TRANSPORT, AND IMPURITIES
Citation Formats
Newman, David E. The dynamics of interacting nonlinearities governing long wavelength driftwave turbulence. United States: N. p., 1993.
Web. doi:10.2172/10103225.
Newman, David E. The dynamics of interacting nonlinearities governing long wavelength driftwave turbulence. United States. https://doi.org/10.2172/10103225
Newman, David E. 1993.
"The dynamics of interacting nonlinearities governing long wavelength driftwave turbulence". United States. https://doi.org/10.2172/10103225. https://www.osti.gov/servlets/purl/10103225.
@article{osti_10103225,
title = {The dynamics of interacting nonlinearities governing long wavelength driftwave turbulence},
author = {Newman, David E.},
abstractNote = {Because of the ubiquitous nature of turbulence and the vast array of different systems which have turbulent solutions, the study of turbulence is an area of active research. Much present day understanding of turbulence is rooted in the well established properties of homogeneous NavierStokes turbulence, which, due to its relative simplicity, allows for approximate analytic solutions. This work examines a group of turbulent systems with marked differences from NavierStokes turbulence, and attempts to quantify some of their properties. This group of systems represents a variety of drift wave fluctuations believed to be of fundamental importance in laboratory fusion devices. From extensive simulation of simple local fluid models of long wavelength drift wave turbulence in tokamaks, a reasonably complete picture of the basic properties of spectral transfer and saturation has emerged. These studies indicate that many conventional notions concerning directions of cascades, locality and isotropy of transfer, frequencies of fluctuations, and stationarity of saturation are not valid for moderate to long wavelengths. In particular, spectral energy transfer at long wavelengths is dominated by the E x B nonlinearity, which carries energy to short scale in a manner that is highly nonlocal and anisotropic. In marked contrast to the canonical selfsimilar cascade dynamics of Kolmogorov, energy is efficiently passed between modes separated by the entire spectrum range in a correlation time. At short wavelengths, transfer is dominated by the polarization drift nonlinearity. While the standard dual cascade applies in this subrange, it is found that finite spectrum size can produce cascades that are reverse directed and are nonconservative in enstrophy and energy similarity ranges. In regions where both nonlinearities are important, crosscoupling between the nolinearities gives rise to large no frequency shifts as well as changes in the spectral dynamics.},
doi = {10.2172/10103225},
url = {https://www.osti.gov/biblio/10103225},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1993},
month = {9}
}