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Main Authors: Albritton, Dallas, Ożański, Wojciech
Format: Preprint
Published: 2023
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Online Access:https://arxiv.org/abs/2310.20674
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author Albritton, Dallas
Ożański, Wojciech
author_facet Albritton, Dallas
Ożański, Wojciech
contents We consider vortex column solutions $v = V(r) e_θ+ W(r) e_z$ to the $3$D Euler equations. We give a mathematically rigorous construction of the countable family of unstable modes discovered by Liebovich and Stewartson (J. Fluid Mech. 126, 1983) via formal asymptotic analysis. The unstable modes exhibit $O(1)$ growth rates and concentrate on a ring $r= r_0$ asymptotically as the azimuthal and axial wavenumbers $n, α\to \infty$ with a fixed ratio. We construct these so-called ring modes with an inner-outer gluing procedure. Finally, we prove that each linear instability implies nonlinear instability for vortex columns. In particular, our analysis yields nonlinear instability for the Batchelor trailing line vortex $V(r) :=\frac{q}{r} (1-\mathrm{e}^{-r^2})$ and $W(r) :=\mathrm{e}^{-r^2}$ when $0<q <\log 2 / \sqrt{1-\log 2} \approx 1.251$.
format Preprint
id arxiv_https___arxiv_org_abs_2310_20674
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Linear and nonlinear instability of vortex columns
Albritton, Dallas
Ożański, Wojciech
Analysis of PDEs
We consider vortex column solutions $v = V(r) e_θ+ W(r) e_z$ to the $3$D Euler equations. We give a mathematically rigorous construction of the countable family of unstable modes discovered by Liebovich and Stewartson (J. Fluid Mech. 126, 1983) via formal asymptotic analysis. The unstable modes exhibit $O(1)$ growth rates and concentrate on a ring $r= r_0$ asymptotically as the azimuthal and axial wavenumbers $n, α\to \infty$ with a fixed ratio. We construct these so-called ring modes with an inner-outer gluing procedure. Finally, we prove that each linear instability implies nonlinear instability for vortex columns. In particular, our analysis yields nonlinear instability for the Batchelor trailing line vortex $V(r) :=\frac{q}{r} (1-\mathrm{e}^{-r^2})$ and $W(r) :=\mathrm{e}^{-r^2}$ when $0<q <\log 2 / \sqrt{1-\log 2} \approx 1.251$.
title Linear and nonlinear instability of vortex columns
topic Analysis of PDEs
url https://arxiv.org/abs/2310.20674