Symmetry breaking of the flow in a cylinder driven by a rotating end wall

The flow driven by a rotating end wall in a cylindrical container with aspe ct ratio H/R=2.5 is time dependent for Reynolds numbers Re=Omega R-2/nu > 2 700. For Reynolds numbers up to 4000 three solution branches have been iden tified, and we examine a solution on each one. At Re=3000, the flow is axis ymmetric and time periodic. At Re=3500, the flow is quasiperiodic with a lo w-frequency modulation and supports a modulated rotating wave with azimutha l wave number k=5. At Re=4000, the flow is time periodic with a qualitative ly different mode of oscillation to that at Re=3500. It also supports a mod ulated rotating wave, with k=6. The peak kinetic energy of the nonaxisymmet ric modes is associated with the jet-like azimuthal flow in the interior. ( C) 2000 American Institute of Physics. [S1070- 6631(00)00311-1].