Application of a new algebraic structure-based model to rotating turbulent flows

A primary goal of RANS based modeling is to determine the Reynolds stress tensor in order to close the turbulence problem at the mean velocity level. However, the Reynolds stresses alone do not characterize adequately the turbulence, especially in presence of rotation; the structure of the turbulence is also important. Here hypothetical turbulent eddies are used to bring awareness of turbulence structure into the turbulence model. Averaging over an ensemble of eddies produces a set of one-point statistics, representative of the eddy field, and a set of equations of state relating the Reynolds stresses to these statistics. An algebraic model for the eddy statistics is constructed in terms of the local mean deformation and two turbulence scales; the turbulent kinetic energy and the large-scale enstrophy (LSE). Contrary to existing ad-hoc definitions of the second scale equation, the LSE equation has a fundamental background; it is derived from the large-scale vorticity equation. The algebraic model is further sensitized to the presence of walls, ensuring proper asymptotic behavior. The complete model has been found to produce very good results for a set of channel flows in fixed frames and in spanwise-rotating frames of reference.