Standing and travelling oscillatory blob convection

Abstract

Results of numerical computations are presented of time-dependent three-dimensional convection flows in a horizontal layer heated from below which evolve from the oscillatory blob instability of steady two-dimensional rolls. It is shown that the heat transport is typically increased in the transition to blob convection. Oscillatory blob convection exists in the forms of standing or travelling blob convection. The latter type of solution represents the stable form bifurcating supercritically at the Rayleigh number RII for the onset of the oscillatory blob instability. In contrast to standing blob convection travelling blob convection exhibits a mean flow.