Effects of a large-scale mean flow in a shell model of turbulent convection

The possible effects of a large-scale mean flow, represented as a non-zero mean velocity in the shell of the largest scale, are studied using a shell model of turbulent convection. In the regime where buoyancy is dynamically important, flow reversals are not observed. On the other hand, flow reversals are found in the regime where buoyancy is not dynamically important. In both regimes, the presence of such a large-scale mean flow does not change the scaling behavior of the velocity and temperature fluctuations.