Intermittency and self-organization in turbulent flows

Eun Jin Kim, Han Li Liu, Johan Anderson

Research output: Contribution to journalConference article

1 Citation (Scopus)

Abstract

We present a statistical theory of self-organization of shear flows, modeled by a nonlinear diffusion equation with a stochastic forcing. A non-perturbative method based on a coherent structure is utilized for the prediction of probability distribution functions (PDFs), showing strong intermittency with exponential tails. We confirm these results by numerical simulations. Furthermore, the results reveal a significant probability of super-critical states due to stochastic perturbation. To elucidate the crucial role of relative time scales of relaxation and disturbance in the determination of PDFs, we present numerical simulation results obtained in a threshold model where the diffusion is given by discontinuous values. Our results highlight the importance of a statistical description of gradients.

Original languageEnglish
Article number014053
JournalPhysica Scripta T
Volume2010
Issue numberT142
DOIs
Publication statusPublished - 31 Dec 2010
Externally publishedYes
Event2nd International Conference and Advanced School on Turbulent Mixing and Beyond, TMB-2009 - Trieste, Italy
Duration: 27 Jul 20097 Aug 2009

Fingerprint

probability distribution functions
Intermittency
intermittency
Self-organization
Turbulent Flow
turbulent flow
Probability Distribution Function
shear flow
disturbances
simulation
Numerical Simulation
perturbation
gradients
Stochastic Perturbation
Threshold Model
Critical State
Coherent Structures
Nonlinear Diffusion Equation
thresholds
Shear Flow

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Mathematical Physics
  • Condensed Matter Physics
  • Physics and Astronomy(all)

Cite this

Intermittency and self-organization in turbulent flows. / Kim, Eun Jin; Liu, Han Li; Anderson, Johan.

In: Physica Scripta T, Vol. 2010, No. T142, 014053, 31.12.2010.

Research output: Contribution to journalConference article

Kim, Eun Jin ; Liu, Han Li ; Anderson, Johan. / Intermittency and self-organization in turbulent flows. In: Physica Scripta T. 2010 ; Vol. 2010, No. T142.
@article{36d32413e4f1437ebc3706663b728afb,
title = "Intermittency and self-organization in turbulent flows",
abstract = "We present a statistical theory of self-organization of shear flows, modeled by a nonlinear diffusion equation with a stochastic forcing. A non-perturbative method based on a coherent structure is utilized for the prediction of probability distribution functions (PDFs), showing strong intermittency with exponential tails. We confirm these results by numerical simulations. Furthermore, the results reveal a significant probability of super-critical states due to stochastic perturbation. To elucidate the crucial role of relative time scales of relaxation and disturbance in the determination of PDFs, we present numerical simulation results obtained in a threshold model where the diffusion is given by discontinuous values. Our results highlight the importance of a statistical description of gradients.",
author = "Kim, {Eun Jin} and Liu, {Han Li} and Johan Anderson",
year = "2010",
month = "12",
day = "31",
doi = "10.1088/0031-8949/2010/T142/014053",
language = "English",
volume = "2010",
journal = "Physica Scripta",
issn = "0031-8949",
publisher = "IOP Publishing Ltd.",
number = "T142",

}

TY - JOUR

T1 - Intermittency and self-organization in turbulent flows

AU - Kim, Eun Jin

AU - Liu, Han Li

AU - Anderson, Johan

PY - 2010/12/31

Y1 - 2010/12/31

N2 - We present a statistical theory of self-organization of shear flows, modeled by a nonlinear diffusion equation with a stochastic forcing. A non-perturbative method based on a coherent structure is utilized for the prediction of probability distribution functions (PDFs), showing strong intermittency with exponential tails. We confirm these results by numerical simulations. Furthermore, the results reveal a significant probability of super-critical states due to stochastic perturbation. To elucidate the crucial role of relative time scales of relaxation and disturbance in the determination of PDFs, we present numerical simulation results obtained in a threshold model where the diffusion is given by discontinuous values. Our results highlight the importance of a statistical description of gradients.

AB - We present a statistical theory of self-organization of shear flows, modeled by a nonlinear diffusion equation with a stochastic forcing. A non-perturbative method based on a coherent structure is utilized for the prediction of probability distribution functions (PDFs), showing strong intermittency with exponential tails. We confirm these results by numerical simulations. Furthermore, the results reveal a significant probability of super-critical states due to stochastic perturbation. To elucidate the crucial role of relative time scales of relaxation and disturbance in the determination of PDFs, we present numerical simulation results obtained in a threshold model where the diffusion is given by discontinuous values. Our results highlight the importance of a statistical description of gradients.

UR - http://www.scopus.com/inward/record.url?scp=79551608657&partnerID=8YFLogxK

U2 - 10.1088/0031-8949/2010/T142/014053

DO - 10.1088/0031-8949/2010/T142/014053

M3 - Conference article

VL - 2010

JO - Physica Scripta

JF - Physica Scripta

SN - 0031-8949

IS - T142

M1 - 014053

ER -