Turbulence model for rotating flows

A second-moment turbulence closure model of the type widely used in modeling geophysical flows is extended to include the effects of rotation on turbulence. The model is the product of a systematic scaling analysis of the Reynolds stress equations in terms of deviations from local isotropy. Both spanwise and axial rotation cases are considered. The model is shown to be conceptually equivalent to, but more self-consistent than, the turbulence models widely used in the simulation of flows in turbomachinery. It is also shown that rotation imparts tensorial properties to eddy viscosity. In the limit of analytically tractable local equilibrium approximation, interesting effects such as complete suppression of turbulence are readily revealed. It is shown that at sufficiently strong destabilizing spanwise rotation, destabilization gives way to restabilization, leading to eventual suppression of turbulence. Also Monin-Obukhov-type similarity theory is applied to the constant flux region of rotating turbulent boundary layers.