### Abstract

Self organization is invoked as a paradigm to explore the processes governing the evolution of shear flows. By examining the probability density function (PDF) of the local flow gradient (shear), we show that shear flows reach a quasi-equilibrium state as its growth of shear is balanced by shear relaxation. Specifically, the PDFs of the local shear are calculated numerically and analytically in reduced 1D and 0D models, where the PDFs are shown to converge to a bimodal distribution in the case of finite correlated temporal forcing. This bimodal PDF is then shown to be reproduced in nonlinear simulation of 2D hydrodynamic turbulence. Furthermore, the bimodal PDF is demonstrated to result from a self-organizing shear flow with linear profile. Similar bimodal structure and linear profile of the shear flow are observed in gulf stream, suggesting self-organization.

Original language | English |
---|---|

Article number | 092306 |

Journal | Physics of Plasmas |

Volume | 20 |

Issue number | 9 |

DOIs | |

Publication status | Published - 24 Sep 2013 |

Externally published | Yes |

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### ASJC Scopus subject areas

- Condensed Matter Physics

### Cite this

*Physics of Plasmas*,

*20*(9), [092306]. https://doi.org/10.1063/1.4817955

**On the self-organizing process of large scale shear flows.** / Newton, Andrew P.L.; Kim, Eun Jin; Liu, Han Li.

Research output: Contribution to journal › Article

*Physics of Plasmas*, vol. 20, no. 9, 092306. https://doi.org/10.1063/1.4817955

}

TY - JOUR

T1 - On the self-organizing process of large scale shear flows

AU - Newton, Andrew P.L.

AU - Kim, Eun Jin

AU - Liu, Han Li

PY - 2013/9/24

Y1 - 2013/9/24

N2 - Self organization is invoked as a paradigm to explore the processes governing the evolution of shear flows. By examining the probability density function (PDF) of the local flow gradient (shear), we show that shear flows reach a quasi-equilibrium state as its growth of shear is balanced by shear relaxation. Specifically, the PDFs of the local shear are calculated numerically and analytically in reduced 1D and 0D models, where the PDFs are shown to converge to a bimodal distribution in the case of finite correlated temporal forcing. This bimodal PDF is then shown to be reproduced in nonlinear simulation of 2D hydrodynamic turbulence. Furthermore, the bimodal PDF is demonstrated to result from a self-organizing shear flow with linear profile. Similar bimodal structure and linear profile of the shear flow are observed in gulf stream, suggesting self-organization.

AB - Self organization is invoked as a paradigm to explore the processes governing the evolution of shear flows. By examining the probability density function (PDF) of the local flow gradient (shear), we show that shear flows reach a quasi-equilibrium state as its growth of shear is balanced by shear relaxation. Specifically, the PDFs of the local shear are calculated numerically and analytically in reduced 1D and 0D models, where the PDFs are shown to converge to a bimodal distribution in the case of finite correlated temporal forcing. This bimodal PDF is then shown to be reproduced in nonlinear simulation of 2D hydrodynamic turbulence. Furthermore, the bimodal PDF is demonstrated to result from a self-organizing shear flow with linear profile. Similar bimodal structure and linear profile of the shear flow are observed in gulf stream, suggesting self-organization.

UR - http://www.scopus.com/inward/record.url?scp=84885086174&partnerID=8YFLogxK

U2 - 10.1063/1.4817955

DO - 10.1063/1.4817955

M3 - Article

VL - 20

JO - Physics of Plasmas

JF - Physics of Plasmas

SN - 1070-664X

IS - 9

M1 - 092306

ER -