Rotating turbulence under "precession-like" perturbation

Eur Phys J E Soft Matter. 2015 Dec;38(12):128. doi: 10.1140/epje/i2015-15128-x. Epub 2015 Dec 7.

Abstract

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.

Keywords: Topical Issue: Multi-scale phenomena in complex flows and flowing matter.