Non-isotropic aspects in homogeneous turbulence subjected to rotation

The subtle effects of uniform rotation on homogeneous turbulence are treated from the point of view of two-points closures. The departure from isotropy is examined in particular, in order to better understand the transition from an isotropic three-dimensional state to a quasi-two-dimensional one. As noted by several authors (including Riley et al., 1981, and Hopfinger et al., 1982), such behavior is expected in both rotating and stratified flows, but up to now it has not been clearly demonstrated by numerical simulations. The analysis shows that the behavior of the Reynolds stress and the length scales is consistent with a trend toward a two-dimensionality in the domain of big structures.