Application of Reynolds Stress Models to Separated Aerodynamic Flows

Several variations of ω-based second-moment Reynolds stress models (RSMs) are applied to two-dimensional and three-dimensional separated aerodynamic flows. In many of these flows, widely used one- and two-equation linear eddy-viscosity turbulence models are known to be inadequate for predicting separated flow characteristics. As potentially important non-linear behavior is naturally included in RSMs, it was hoped that they might improve the separated flow predictions. However, the RSMs perform no better than the simpler models for these particular flows. Like the simpler models, the RSMs predict too little turbulence in the separated shear layer of the two-dimensional flow over a hump, which is indicative of modeling deficiencies for this class of flows. Nonetheless, the best RSM version tested offers a convenient framework for possible future model improvements.