Navier-Stokes bounds and scaling for compact trefoils in $(2\ell\pi)^3$ domains
Abstract
For a perturbed trefoil vortex knot evolving under the Navier-Stokes equations, a sequence of -independent times are identified corresponding to a set of scaled, volume-integrated vorticity moments with this hierarchy and . For the volume-integrated enstrophy, convergence of at marks the end of the reconnection scaling phase. Physically, reconnection follows from the formation of a double vortex sheet, then a knot, which splits into spirals. then accelerates, leading to approximate finite-time -independent convergence of the energy dissipation rate at and sustained over a finite span , giving Reynolds number independent finite-time, dissipation, , and thus satisfying one definition for a {\it dissipation anomaly}. Evidence for transient Kolmogorov-like enstrophy spectra is found over . A critical factor in achieving these temporal convergence laws is how the domain is increased as , for to 6, then to , as decreases. domain compatibility with established mathematics in appendix allows small Navier-Stokes solutions. Two spans of are considered. Over the first factor of 25 decrease in , all of the converge to their respective . For the next factor of 5 decrease in , is increased to , there is only convergence of to and later convergence at and over .
Keywords
Cite
@article{arxiv.2401.03578,
title = {Navier-Stokes bounds and scaling for compact trefoils in $(2\ell\pi)^3$ domains},
author = {Robert M. Kerr},
journal= {arXiv preprint arXiv:2401.03578},
year = {2025}
}
Comments
21 pages, 9 frames in 7 figures