A model for vortical plumes in rotating convection

Heat flux intensification by vortical flow localization in rotating convection.

The effect of rotation on turbulent convective flow between parallel plates has been assessed with direct numerical simulations. With increasing rotation-rate an interesting transition is observed in the vertical-velocity skewness. This transition indicates a localization of motion directed away from the wall and correlates well with changes observed in the heat flux, as well as in the thermal ...

Hexagonal Patterns in a Model for Rotating convection

We study a model equation that mimics convection under rotation in a fluid with temperaturedependent properties (non-Boussinesq (NB)), high Prandtl number and idealized boundary conditions. It is based on a model equation proposed by Segel [1965] by adding rotation terms that lead to a Kiippers-Lortz instability [Kuppers & Lortz, 1969] and can develop into oscillating hexagons. We perform a wea...

Plumes in stellar convection zones

All numerical simulations of compressible convection reveal the presence of strong downwards directed flows. Thanks to helioseismology, such plumes have now been detected also at the top of the solar convection zone, on supergranular scales. Their properties may be crudely described by adopting Taylor’s turbulent entrainment hypothesis, whose validity is well established under various condition...

Gravity Wave Generation by Vortical Flows in a Rotating Frame

Studies in Rotating Convection

This thesis presents an exploration and analysis of novel phenomena in RayleighBénard convection in a rotating cylinder using direct numerical simulation and equivariant bifurcation analysis. The numerical method used is a second order predictorcorrector method using Chebyshev collocation in the radial and axial directions and a Fourier-Galerkin discretization in the azimuthal direction. This n...