The Influence of Vertical Vorticity on Thermal Convection

Abstract

The single-mode equations of Boussinesq thermal convection have been modified to include the vertical component of vorticity, which has led, in certain parameter ranges, to a new family of solutions for stationary convection in the absence of external constraints. The features of these solutions are discussed and a comparison with the family of solutions possessing zero vertical vorticity, which are also solutions of the equations, is presented. Specifically, these new solutions are characterized by a lower vertical velocity and heat flux, nonzero vertical vorticity thereby giving them a helical structure and considerably reduced thermal boundary layers in comparison with the family of solutions with zero vertical vorticity. It is to be stressed that this new family of solutions is not due to externally applied influences such as rotation or a magnetic field, the only driving force present being that due to buoyancy.