### Abstract

Isotropic turbulence is examined for the existence of conditional flow structures by computing estimates of the velocity u(x + r, t) given that the velocity at (x, t) assumes some specified value, u(x, t). In general, the best mean-square estimate of u(x + r, t) is the conditional average 〈u(x + r, t)| u(x, t)〉. This quantity is approximated in terms of second- and third-order two-point spatial correlations using nonlinear estimation techniques. The estimate predicts conditional eddies that are vortex rings axisymmetric about the direction of u(x, t). Averaging these estimates over all values of u(x, t) yields two-point moments that are correct through third order.

Original language | English (US) |
---|---|

Pages (from-to) | 2065-2070 |

Number of pages | 6 |

Journal | Physics of Fluids |

Volume | 22 |

Issue number | 11 |

State | Published - 1979 |

Externally published | Yes |

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### ASJC Scopus subject areas

- Condensed Matter Physics
- Physics and Astronomy(all)
- Mechanics of Materials
- Computational Mechanics
- Fluid Flow and Transfer Processes
- Engineering(all)

### Cite this

*Physics of Fluids*,

*22*(11), 2065-2070.

**Conditional eddies in isotropic turbulence.** / Adrian, Ronald.

Research output: Contribution to journal › Article

*Physics of Fluids*, vol. 22, no. 11, pp. 2065-2070.

}

TY - JOUR

T1 - Conditional eddies in isotropic turbulence

AU - Adrian, Ronald

PY - 1979

Y1 - 1979

N2 - Isotropic turbulence is examined for the existence of conditional flow structures by computing estimates of the velocity u(x + r, t) given that the velocity at (x, t) assumes some specified value, u(x, t). In general, the best mean-square estimate of u(x + r, t) is the conditional average 〈u(x + r, t)| u(x, t)〉. This quantity is approximated in terms of second- and third-order two-point spatial correlations using nonlinear estimation techniques. The estimate predicts conditional eddies that are vortex rings axisymmetric about the direction of u(x, t). Averaging these estimates over all values of u(x, t) yields two-point moments that are correct through third order.

AB - Isotropic turbulence is examined for the existence of conditional flow structures by computing estimates of the velocity u(x + r, t) given that the velocity at (x, t) assumes some specified value, u(x, t). In general, the best mean-square estimate of u(x + r, t) is the conditional average 〈u(x + r, t)| u(x, t)〉. This quantity is approximated in terms of second- and third-order two-point spatial correlations using nonlinear estimation techniques. The estimate predicts conditional eddies that are vortex rings axisymmetric about the direction of u(x, t). Averaging these estimates over all values of u(x, t) yields two-point moments that are correct through third order.

UR - http://www.scopus.com/inward/record.url?scp=0018304132&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0018304132&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0018304132

VL - 22

SP - 2065

EP - 2070

JO - Physics of Fluids

JF - Physics of Fluids

SN - 1070-6631

IS - 11

ER -