Contents | PDF file (300 KB)

ESAIM: Proceedings, Vol. 7, 1999, 270-279
Third International Workshop on Vortex Flows
and Related Numerical Methods
http://www.emath.fr/proc/Vol.7/

The different equations of motion of the central line of a slender vortex filament
and their use to study perturbed vortices

D. MARGERIT AND J-P. BRANCHER

LEMTA (CNRS UMR 7563)
2 avenue de la forêt de Haye BP 160
54504 Vandoeuvre les Nancy, France.

dmargeri@ensem.u-nancy.fr

Abstract:

A comparison between the equation of motion of the central line of a slender vortex filament deduced from a matched asymptotic expansion[1] and the expansion of the equation of motion of the ad-hoc cut-off methods[2] with the cut-off length as the small asymptotic parameter is performed. It justifies the cut-off methods and gives the link between the cut-off lengths and the thickness of a viscous or inviscid vortex with an axial velocity component. The asymptotic equation of motion for an open filament is then simplified in case of a perturbed straight filament and different regimes are displayed. They depend of relatives values of the amplitude of the perturbation and the small thickness of the filament.
  Contents | PDF file(300 KB)