## Abstract / Description of output

The robustness of steady solutions of the Euler equations for two-dimensional, incompressible and inviscid fluids is examined by studying their persistence for small deformations of the fluid-domain boundary. Starting with a given steady flow in a domain D-0, we consider the class of flows in a deformed domain D that can be obtained by rearrangement of the vorticity by an area-preserving diffeomorphism.

We provide conditions for the existence and (local) uniqueness of a steady flow in this class when D is sufficiently close to D-0 in C-k,C-alpha k >= 3 and 0 < alpha < 1. We consider first the case where D-0 is a periodic channel and the flow in D-0 is parallel and show that the existence and uniqueness are ensured for flows with non-vanishing velocity. We then consider the case of smooth steady flows in a more general domain D-0. The persistence of the stability of steady flows established using the energy-Casimir or, in the parallel case, the energy-Casimir-momentum method, is also examined. A numerical example of a steady flow obtained by deforming a parallel flow is presented.

Original language | English |
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Pages (from-to) | 2657-2680 |

Number of pages | 24 |

Journal | Nonlinearity |

Volume | 18 |

Issue number | 6 |

DOIs | |

Publication status | Published - Nov 2005 |

## Keywords / Materials (for Non-textual outputs)

- IDEAL FLUID
- EQUATION