Reynolds Stress Relaxation Turbulence Modeling Applied to a Wingtip Vortex Flow

A Reynolds stress relaxation model, specifically the lag Reynolds stress transport model, is applied to a wingtip vortex flow, and its performance is assessed and compared with other aerospace standard turbulence models. A Reynolds stress relaxation model allows for Reynolds stress history effects due to streamline curvature, which are seen to play an important role in the nondiffusive nature of turbulent vortices. This study shows that the lag Reynolds stress transport turbulence model is capable of predicting mean flow results as accurately as those of the well-performing Spalart–Allmaras model with correction for streamline curvature and system rotation. Furthermore, in this wingtip vortex flow, the lag Reynolds stress transport model predicts turbulence quantities more accurately than the rotation/curvature-corrected Spalart–Allmaras model. Although the lag Reynolds stress transport model well predicts this flow, it is more computationally intensive to solve than the rotation/curvature-corrected Spalart–Allmaras model, and it has some deficiencies, such as an inability to independently control the Reynolds stress magnitude and relaxation amount.