## Abstract

Statistical characteristics of freely decaying two-dimensional hydrodynamic turbulence at high Reynolds numbers are numerically studied. In particular, numerical experiments (with resolution up to 8192 × 8192) provide a Kraichnan-type turbulence spectrum E_{k} ~ k^{-3}. By means of spatial filtration, it is found that the main contribution to the spectrum comes from sharp vorticity gradients in the form of quasi-shocks. Such quasi-singularities are responsible for a strong angular dependence of the spectrum owing to well-localized (in terms of the angle) jets with minor and/or large overlapping. In each jet, the spectrum decreases as k^{-3}. The behavior of the third-order structure function accurately agrees with the Kraichnan direct cascade concept corresponding to a constant enstrophy flux. It is shown that the power law exponents ξ_{n} for higher structure functions grow with n more slowly than the linear dependence, thus indicating turbulence intermittency.

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

Pages (from-to) | 699-705 |

Number of pages | 7 |

Journal | JETP Letters |

Volume | 96 |

Issue number | 11 |

DOIs | |

Publication status | Published - Feb 2013 |