@Article{cmes.2025.072000,
AUTHOR = {Mehmet Numan Kaya},
TITLE = {Shock-Boundary Layer Interaction in Transonic Flows: Evaluation of Grid Resolution and Turbulence Modeling Effects on Numerical Predictions},
JOURNAL = {Computer Modeling in Engineering \& Sciences},
VOLUME = {145},
YEAR = {2025},
NUMBER = {1},
PAGES = {327--343},
URL = {http://www.techscience.com/CMES/v145n1/64359},
ISSN = {1526-1506},
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<sup>+</sup>) 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 × 10<sup>6</sup>, 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  meshes with deviations below 0.02 compared to the experiment, and maintaining accuracy even at y<sup>+</sup> ≈ 5. The k-ε‌ Realizable model was highly sensitive to near-wall resolution, displacing shocks downstream at higher y<sup>+</sup> 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<sup>+</sup> ≈ 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.},
DOI = {10.32604/cmes.2025.072000}
}