The spiral form of vortex breakdown observed in the numerical simulations of Ruith et al. ( J. Fluid Mech. , vol. 486, 2003, p. 331) is interpreted as a nonlinear global mode originating at the convective/absolute instability transition point in the lee of the vortex breakdown bubble. The local absolute frequency at the transition station is shown to yield a satisfactory prediction of the precession frequency measured in the three-dimensional direct numerical simulations.
No takes yet. Share an insight, caveat, or question.
Gallaire et al. (2006) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: