Extreme multiplicity in cylindrical Rayleigh-Bénard convection. I. Time dependence and oscillations.

Rayleigh-Bénard convection in a cylindrical container can take on many different spatial forms. Motivated by the results of Hof [Phys. Fluids 11, 2815 (1999)], who observed coexistence of several stable states at a single set of parameter values, we have carried out simulations at the same Prandtl number, that of water, and a radius-to-height aspect ratio of two. We have used two kinds of thermal boundary conditions: perfectly insulating sidewalls and perfectly conducting sidewalls. In both cases we obtain a wide variety of coexisting steady and time-dependent flows.