Rotating turbulence under "precession-like" perturbation

Kartik P. Iyer, Irene Mazzitelli, Fabio Bonaccorso, Annick Pouquet, Luca Biferale

Published 2015-11-19Version 1

The effects of changing the orientation of the rotation axis on homogeneous turbulence is considered. We perform direct numerical simulations on a periodic box of $1024^3$ grid points, where the orientation of the rotation axis is changed (a) at a fixed time instant (b) regularly at time intervals commensurate with the rotation time scale. The former is characterized by a dominant inverse energy cascade whereas in the latter, the inverse cascade is stymied due to the recurrent changes in the rotation axis resulting in a strong forward energy transfer and large scale structures that resemble those of isotropic turbulence.