Turbulence in Stars. II. Shear, Stable Stratification, and Radiative Losses

For many years shear-driven turbulence was thought to provide sufficient turbulent mixing in stably stratified regions to explain stellar structure data. It has recently been argued that the mixing is too weak and that alternative mixing mechanisms are required. The conclusion is predicated, among others, on the key assumption that turbulence exists only for Ri 1 (no radiative losses) Ricr ~ 1, while for Pe limit. However, without a specific application of the model to a stellar case, we cannot claim that the new model will provide the mixing required by stellar data.