Physical Sciences and Mathematics Commons^™

Convectively Driven Shear And Decreased Heat Flux, David Goluskin, Hans Johnston, Glenn R. Flierl, Edward A. Spiegel

Hans Johnston

We report on direct numerical simulations of two-dimensional, horizontally periodic Rayleigh–Bénard convection between free-slip boundaries. We focus on the ability of the convection to drive large-scale horizontal flow that is vertically sheared. For the Prandtl numbers (Pr) between 1 and 10 simulated here, this large-scale shear can be induced by raising the Rayleigh number (Ra) sufficiently, and we explore the resulting convection for Ra up to 1010. When present in our simulations, the sheared mean flow accounts for a large fraction of the total kinetic energy, and this fraction tends towards unity as Ra→∞. The shear helps disperse convective structures, …