Coupling Two Correlation-Based Transition Models to the kSkL Eddy Viscosity Turbulence Model

When dealing with flows at moderate Reynolds numbers, the laminar and transition regions are a key component of the flow solution. In applications such as wind turbines and unmanned aerial vehicles, an accurate prediction of the aerodynamic forces requires accounting for these effects. In Reynolds-averaged Navier–Stokes simulations, this is done by incorporating transition models because commonly used turbulence models are unable to predict a significant extent of laminar flow. In this paper, we present and study the coupling of the local correlation-based ɣ-Re_θ and ɣ transition models with the k-√kL (KSKL) turbulence model, and we compare it to the original formulation using the k-ω shear-stress transport (SST) turbulence model. The coupling of the models is calibrated for the flow over a flat plate and subsequently tested for the flow around the S809 and NLF(1)-0416 airfoils, as well as around a 6:1 prolate spheroid. The results show that the combination of the ɣ-Re_θ transition model with the KSKL turbulence model leads to a reduction of the numerical uncertainty (discretization errors) when compared to its application with the SST model. On the other hand, the combination of the KSKL model with the ɣ transition model leads to the sharpest transition of the four combinations tested.