Utilizing a Spalart-Allmaras Turbulence Model Correction with a Transition Model

A correction to the popular Spalart-Allmaras turbulence model for low Reynolds numbers is applied with the Amplification Factor Transport transition model to evaluate the corrected model’s improvements in the low-Reynolds number regime. The correction implementation is validated on a flat plate and compared with published results. Results with the transition model are also presented and show similar trends post-transition, where the local skin friction is higher with the new correction. The standard and corrected Spalart-Allmaras turbulence models, coupled with the Amplification Factor Transport transition model, are then used to analyze the E 387 airfoil and compared with experimental data from NASA Langley and The Pennsylvania State University. The corrected turbulence model has little effect at a Reynolds number of 4.6 × 105, but the impact increases slightly as the Reynolds number decreases. The corrected model predicts lower drag at certain conditions relative to the standard Spalart-Allmaras model. This is shown to be due to the corrected model reducing the airfoil pressure drag more than it increases the skin friction drag.