Spiral vortex breakdown as a global mode

F. Gallaire (1) , M. Ruith (2) , E. Meiburg (2) , Jean-Marc Chomaz (3) , Patrick Huerre (3)

1 LJAD - Laboratoire Jean Alexandre Dieudonné
2 Department of Mechanical and Environmental Engineering, USCB, Santa Barbara, CA 93106, United States
3 LadHyX - Laboratoire d'hydrodynamique

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. © 2006 Cambridge University Press.

Domains: Fluid mechanics [physics.class-ph]; Fluids mechanics [physics.class-ph]; Fluid Dynamics [physics.flu-dyn]

F. Gallaire, M. Ruith, E. Meiburg, Jean-Marc Chomaz, Patrick Huerre. Spiral vortex breakdown as a global mode. Journal of Fluid Mechanics, 2006, 549 (february), pp.71-80. ⟨10.1017/s0022112005007834⟩. ⟨hal-01023370⟩