Global time evolution of concentrated vortex rings
Paolo Buttà, Guido Cavallaro, Carlo Marchioro
备注:
23 pages, LaTex; small changes in abstract and introduction, typos corrected, added an appendix with the proof of Lemma 4.1, and, with respect to version 2, Lemma 3.2 corrected (which implies very slight changes in other parts of the manuscript). This article is an extension of the results arXiv:1904.04785 and therefore draws heavily from arXiv:1904.04785
We study the time evolution of 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 $\varepsilon$ and vorticity mass of the order of $|\log\varepsilon|^{ -1}$. When $\varepsilon \to 0$ we show that the motion of each vortex ring converges to a simple translation with constant speed (depending on the single ring) along the symmetry axis. We obtain a sharp localization of the vorticity support at time $t$ in the radial direction, whereas we state only a concentration property in the axial direction. This is obtained for arbitrary (but fixed) intervals of time. This study is the completion of a previous paper arXiv:1904.04785 [math-ph], where a sharp localization of the vorticity support was obtained both along the radial and axial directions, but the convergence for $\varepsilon\to 0$ worked only for short times.
Uniqueness and stability of steady vortex rings for 3D incompressible Euler equation
Institute of Applied Mathematics, Chinese Academy of Sciences(中国科学院应用数学研究所);University of Chinese Academy of Sciences(中国科学院大学);School of Mathematical Sciences, Xiamen University(厦门大学数学科学学院);Department of Mathematics, Sichuan University(四川大学数学系)
Academy of Mathematics and Systems Science, Chinese Academy of Sciences(中国科学院数学与系统科学研究院);Department of Mathematical Sciences and RIM, Seoul National University(首尔大学数学科学系及RIM);School of Mathematics, Korea Institute for Advanced Study(韩国高等研究院数学学院);School of Mathematical Sciences, University of Science and Technology of China(中国科学技术大学数学科学学院)