Colloquia

Summary

Laminar–turbulent transition significantly influences the aerodynamic performance of aircraft wings, especially in terms of drag that is experienced by the wing. Accurately predicting this transition is essential for designing more efficient aerodynamic designs. However, due to its inherent complexity, modeling the laminar-to-turbulent transition within CFD RANS frameworks while maintaining manageable computational cost is a challenging task.

Currently, the leading approach for engineering applications involves employing transition transport models, which control the base turbulence model to capture transition phenomena. In this study, a code comparison is conducted between two such transition-transport models across two CFD solvers.

This comparative analysis validates the implementation of both models in the respective codes and highlights their predictive capability for modeling the transition process within the RANS framework. The solvers considered are TAU, a proprietary code developed by the German Aerospace Center (DLR) and SU2, an open-source, community-driven framework.

Within these solvers, both the established γ–Reθ model by Langtry and Menter (2009), and a novel one-equation γ-model developed by Ströer et al. (2022) are evaluated, analyzing implementation considerations and performance across solvers. For this purpose, the one-equation γ-model has been implemented to the SU2 code. It could be shown that through careful selection of solver settings and consistent implementation of the turbulence models, near-perfect agreement between the two codes was achieved across all test cases. This outcome validates the one-equation γ-model developed by Ströer et al. (2022) for the test case, while the γ–Reθ model by Langtry and Menter (2009) exhibited larger deviations from experimental observations.