DNS of Convective Heat Transfer in a Rotating Cylinder

The effects of rotation on the convective heat transfer and flow structuring in a cylindrical volume of fluid is investigated with direct numerical simulation (DNS). A formulation of the discrete equations of motion in cylindrical coordinates is solved with finite-difference approximations. At constant Rayleigh (Ra; dimensionless temperature gradient) and Prandtl (sigma; characterises diffusive properties of the fluid) numbers, the Rossby number Ro, the ratio of buoyancy and Coriolis forces, is varied between runs with 0.045 less than or similar to Ro less than or similar to infinity. For Ro greater than or similar to 1.2 we find the so-called large-scale circulation. At Ro less than or similar to 1.2 slender columnar vortical plumes are found. In a range of Ro heat transfer is increased by Ekman pumping in the vortical plumes.