The roles of shear and cross-correlations on the fluctuation levels in simple stochastic models. Revision

Krommes, J A

doi:10.2172/751203

Title: The roles of shear and cross-correlations on the fluctuation levels in simple stochastic models. Revision

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Abstract

Highly simplified models of random flows interacting with background microturbulence are analyzed. In the limit of very rapid velocity fluctuations, it is shown rigorously that the fluctuation level of a passively advected scalar is not controlled by the rms shear. In a model with random velocities dependent only on time, the level of cross-correlations between the flows and the background turbulence regulates the saturation level. This effect is illustrated by considering a simple stochastic-oscillator model, both exactly and with analysis and numerical solutions of the direct-interaction approximation. Implications for the understanding of self-consistent turbulence are discussed briefly.

Authors:: Krommes, J A

Publication Date:: Wed Nov 03 00:00:00 EST 1999

Research Org.:: Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

Sponsoring Org.:: USDOE Office of Energy Research (ER) (US)

OSTI Identifier:: 751203

Report Number(s):: PPPL-3377Revised
TRN: US0000897

DOE Contract Number:: AC02-76CH03073

Resource Type:: Technical Report

Resource Relation:: Other Information: PBD: 3 Nov 1999

Country of Publication:: United States

Language:: English

Subject:: 70 PLASMA PHYSICS AND FUSION; PLASMA SIMULATION; TIME DEPENDENCE; TURBULENCE; STOCHASTIC PROCESSES; SHEAR; PLASMA DRIFT

Citation Formats


                    Krommes, J A. The roles of shear and cross-correlations on the fluctuation levels in simple stochastic models. Revision.  United States: N. p., 1999. 
        Web.  doi:10.2172/751203.

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                    Krommes, J A. The roles of shear and cross-correlations on the fluctuation levels in simple stochastic models. Revision.  United States.  https://doi.org/10.2172/751203

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                    Krommes, J A. 1999.  
        "The roles of shear and cross-correlations on the fluctuation levels in simple stochastic models. Revision".  United States.  https://doi.org/10.2172/751203.  https://www.osti.gov/servlets/purl/751203.

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@article{osti_751203,

  title        = {The roles of shear and cross-correlations on the fluctuation levels in simple stochastic models. Revision},

  author       = {Krommes, J A},

  abstractNote = {Highly simplified models of random flows interacting with background microturbulence are analyzed. In the limit of very rapid velocity fluctuations, it is shown rigorously that the fluctuation level of a passively advected scalar is not controlled by the rms shear. In a model with random velocities dependent only on time, the level of cross-correlations between the flows and the background turbulence regulates the saturation level. This effect is illustrated by considering a simple stochastic-oscillator model, both exactly and with analysis and numerical solutions of the direct-interaction approximation. Implications for the understanding of self-consistent turbulence are discussed briefly.},

  doi          = {10.2172/751203},

  url          = {https://www.osti.gov/biblio/751203},
  journal      = {},
number       = ,

  volume       = ,

  place        = {United States},

  year         = {Wed Nov 03 00:00:00 EST 1999},

  month        = {Wed Nov 03 00:00:00 EST 1999}

}

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