SPATIOTEMPORAL STRUCTURES IN PHASE-TURBULENT CONVECTION

The problem of phase turbulence for convection in a horizontal layer heated from below with stress-free boundaries is considered in the case of low Prandtl numbers P when steady rolls become unstable to the monotone or oscillatory skewed varicose instabilities. Numerical computations are reported for a square horizontal periodicity interval with finite aspect ratio GAMMA. Transitions to chaotic solutions occur when GAMMA exceeds a value of the order 8. Various three-dimensional steady and time periodic solutions can be described by a reduced set of differential equations in time. In particular the evolution of convection flows induced by the monotone skewed varicose instability is followed in detail.