Direct numerical simulation of Nusselt number scaling in rotating Rayleigh-Bénard convection

We report results from Direct Numerical Simulation (DNS) of rotating Rayleigh-Bénard convection, regarding the scaling of heat transfer with the Rayleigh number for rotating systems at a fixed rate of rotation. The Prandtl number, Pr=6.4, is kept constant. We perform simulations, using a spectral element method, for Rayleigh numbers Ra from 106 to 109, and Rossby numbers Ro from 0.09 to ∞. We find that the Nusselt number Nu scales approximately with a power 2/7 of Ra at sufficiently high Ra for all Ro. The value of Ra beyond which this Nusselt scaling is well established increases with decreasing Ro. Depending on the rotation rate, the Nusselt number can increase up to 18% with respect to the non-rotating case.