Julie Albagnac
David Laupsien
Dominique Anne-Archard
Institut de Mécanique des Fluides de Toulouse
Toulouse, FRANCE

Image by J. Albagnac, D. Laupsien and D. Anne-Archard, IMFT, France

Are vortex rings always the same (from a topological and/or dynamical point of view)? no!

It is now well known that both topology and dynamics of such a vortical structure strongly depend on the generation conditions. The present study focuses on the effect of the fluid nature itself. Indeed, despite the same generation conditions (same piston-cylinder apparatus + same stroke ratio ending to the same relative position to the cylinder exit) and the same inertial effect (same generalized Reynolds number), Figures 1 and 2 highlight the strong influence of the fluid nature on annular vortex behavior. Figure 1 shows obvious different topologies for Newtonian (left) and viscoelastic (right) vortex rings. Figure 2 presents a time evolution of a vortex ring in a Newtonian (top) and viscoelastic (bottom) fluid. Newtonian vortex ring furls, propagates by auto-induced effect and diffuses (increase of its diameter) while propagating. Non-Newtonian viscoelastic vortex ring, instead, first furls and expends as it is propagating away then stops, unfurls and goes back, contracting in the radial direction.

Abstract Link

http://meeting.aps.org/Meeting/DFD14/Session/L18.12

Usage Information

These images may be freely reproduced with the accompanying credit: "Image by J. Albagnac, D. Laupsien and D. Anne-Archard, IMFT, France"

Contact Information

Julie Albagnac
Institut de Mécanique des Fluides de Toulouse
Toulouse, FRANCE
julie.albagnac@imft.fr