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arXiv · 2310.00732

Leapfrogging vortex rings as scaling limit of Euler Equations

Paolo Buttà·Guido Cavallaro·Carlo Marchioro
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Abstract

We consider an incompressible fluid with axial symmetry without swirl, assuming initial data such that the initial vorticity is very concentrated inside $N$ small disjoint rings of thickness $\varepsilon$, each one of vorticity mass and main radius of order $|\log\varepsilon|$. When $\varepsilon \to 0$, we show that, at least for small but positive times, the motion of the rings converges to a dynamical system firstly introduced in [NoDEA Nonlinear Diff. Eq. Appl. 6 (1999), 473-499]. In the special case of two vortex rings with large enough main radius, the result is improved reaching longer times, in such a way to cover the case of several overtakings between the rings, thus providing a mathematical rigorous derivation of the leapfrogging phenomenon.

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Paolo Buttà, Guido Cavallaro, Carlo Marchioro. 2023-10-01. Leapfrogging vortex rings as scaling limit of Euler Equations. https://doi.org/10.1137/24m164239

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