@article{Kaya2025, 
author = {Mehmet Numan Kaya},
title = {Shock-Boundary Layer Interaction in Transonic Flows: Evaluation of Grid Resolution and Turbulence Modeling Effects on Numerical Predictions},
year = {2025},
journal = {Computer Modeling in Engineering & Sciences},
volume = {145},
number = {1},
pages = {327-343},
keywords = {Transonic, CFD, shock, RAE2822, airfoil, aerodynamics},
url = {https://www.sciopen.com/article/10.32604/cmes.2025.072000},
doi = {10.32604/cmes.2025.072000},
abstract = {This study investigates the influence of mesh resolution and turbulence model selection on the accuracy of numerical simulations for transonic flow, with particular emphasis on shock-boundary layer interaction phenomena. Accurate prediction of such flows is notoriously difficult due to the sensitivity to near-wall resolution, global mesh density, and turbulence model assumptions, and this problem motivates the present work. Two solvers were employed, rhoCentralFoam (unsteady) and TSLAeroFoam (steady-state), both are compressible and density-based and implemented within the OpenFOAM framework. The investigation focuses on three different non-dimensional wall distance ( y+) values of 1, 2.5 and 5, each implemented with both moderate and fine mesh resolutions. Three turbulence models—Spalart-Allmaras (SA),  k- ω Shear Stress Transport (SST), and  k- ϵ Realizable—were evaluated at M = 0.74, Re = 2.7  × 106, and  α =  3.19∘. Results showed that while both solvers achieved good overall agreement with experimental data, particularly in terms of pressure distribution, lift coefficient, and shock location, noticeable differences still emerged. The  k- ω SST model consistently delivered the most robust performance across all cases, capturing the shock position on  y+≈1 meshes with deviations below 0.02 c compared to the experiment, and maintaining accuracy even at  y+≈5. The  k- ϵ Realizable model was highly sensitive to near-wall resolution, displacing shocks downstream at higher  y+ values, whereas Spalart-Allmaras remained broadly comparable to the  k- ω SST model in predictive performance. The rhoCentralFoam solver achieved consistently better lift predictions, staying within about 2% of the experimental value on average, whereas TSLAeroFoam overpredicted it by around 4%. For transonic Reynolds-Averaged Navier-Stokes (RANS) simulations, unsteady  k- ω SST with  y+≈1 is recommended for maximum fidelity, whereas steady  k- ω SST or SA simulations offer a practical option for quick and reasonably accurate aerodynamic predictions.}
}