Asymptotic vorticity structure and numerical simulation of slender vortex filaments


Journal Article

A new asymptotic analysis of slender vortices in three dimensions, based solely on the vorticity transport equation and the non-local vorticity-velocity relation gives new insight into the structure of slender vortex filaments. The approach is quite different from earlier analyses using matched asymptotic solutions for the velocity field and it yields additional information. This insight is used to derive three different modifications of the thin-tube version of a numerical vortex element method. Our modifications remove an 0(1) error from the node velocities of the standard thin-tube model and allow us to properly account for any prescribed physical vortex core structure independent of the numerical vorticity smoothing function. We demonstrate the performance of the improved models by comparison with asymptotic solutions for slender vortex rings and for perturbed slender vortex filaments in the Klein-Majda regime, in which the filament geometry is characterized by small-amplitude-short-wavelength displacements from a straight line. These comparisons represent a stringent mutual test for both the proposed modified thin-tube schemes and for the Klein-Majda theory. Importantly, we find a convincing agreement of numerical and asymptotic predictions for values of the Klein-Majda expansion parameter e as large as f. Thus, our results support their findings in earlier publications for realistic physical vortex core sizes. © 1995, Cambridge University Press. All rights reserved.

Full Text

Duke Authors

Cited Authors

  • Klein, R; Knio, O

Published Date

  • January 1, 1995

Published In

Volume / Issue

  • 284 /

Start / End Page

  • 275 - 321

Electronic International Standard Serial Number (EISSN)

  • 1469-7645

International Standard Serial Number (ISSN)

  • 0022-1120

Digital Object Identifier (DOI)

  • 10.1017/S002211209500036X

Citation Source

  • Scopus