Abstract
Vortex breakdown of bubble type is studied for the flow in a cylinder with rotating top
and bottom covers. For large ratios of the angular velocities of the covers, we observe numerically that
the vortex breakdown bubble in the steady regime may occur through the creation of an off-axis vortex
ring. This scenario does not occur in existing bifurcation theory based on a simple degeneracy in the flow
field. We extend the theory to cover a non-simple degeneracy, and derive the associated bifurcation
diagrams. We show that the vortex breakdown scenario involving a vortex ring can be explained from this
theory, and that the numerically generated bifurcation diagrams are consistent with the theory.
Original language | English |
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Journal | Acta Mechanica |
Volume | 187 |
Pages (from-to) | 75-83 |
ISSN | 0001-5970 |
DOIs | |
Publication status | Published - 2006 |