### 抜粋

We revisit, with some extension to the nonlinear regime, the Moore-Saffman-Tsai-Widnall instability, which is the three-dimensional instability of a straight vortex tube elliptically strained by a pure shear flow. A circular cylindrical vortex tube supports neutrally stable three-dimensional waves called Kelvin waves. A pure shear breaks the circular symmetry, causing a parametric resonance between two Kelvin waves whose azimuthal wavenumbers are separated by two. The eigenvalues and functions are written out in full in terms of the Bessel and the modified Bessel functions, and so is the growth rate. That this instability has a link with the elliptical instability in the short-wave limit is established in this study. This result is studied in the light of Krein's theory for Hamiltonian spectra. We develop a Lagrangian (particle) formulation that makes feasible an efficient calculation of iso-vortical disturbances up to second order in amplitude and thereby facilitates calculation of the energy of Kelvin waves. It is found that a Kelvin wave induces a drift current along the vortex tube.

元の言語 | 英語 |
---|---|

記事番号 | 014041 |

ジャーナル | Physica Scripta T |

巻 | T132 |

DOI | |

出版物ステータス | 出版済み - 12 1 2008 |

イベント | International Conference 'Turbulent Mixing and Beyond' - Trieste, イタリア 継続期間: 8 18 2007 → 8 26 2007 |

### All Science Journal Classification (ASJC) codes

- Atomic and Molecular Physics, and Optics
- Mathematical Physics
- Condensed Matter Physics

## フィンガープリント Elliptical instability of a vortex tube and drift current induced by it' の研究トピックを掘り下げます。これらはともに一意のフィンガープリントを構成します。

## これを引用

*Physica Scripta T*,

*T132*, [014041]. https://doi.org/10.1088/0031-8949/2008/T132/014041