Near-wall Reynolds-stress modelling in noninertial frames of reference

Second-moment closure predictions of fully developed turbulent Poiseuille and Couette flow subjected to spanwise rotation are verified against direct numerical and large eddy simulations in addition to recent experimental results. Near-wall effects are modelled by elliptic relaxation which is used in conjunction with a nonlinear, variable-coefficient pressure strain model consistent with the principle of material frame indifference (MFI) in the limit of two-dimensional turbulence. The dissipation rate model equation is modified in the near-wall region to become explicitly dependent on the imposed system rotation, however, without violating the MFI principle. The model predictions exhibit many of the features due to the Coriolis force on the turbulence and mean flow field, respectively. These include an almost irrotational region in the channel core, augmentation of the turbulence on the unstable side and a corresponding reduction on the stable side, relaminarisation caused not only by stabilising rotation but also by sufficiently high destabilising rotation in Couette flow and, finally, localised regions in the core of the Poiseuille flow where mean flow energy is extracted from the turbulence. The effects of rotational-induced secondary motions on the flow field are also addressed.