Influence of Turbulence Modelling and Grid Resolution In Computations of the DPW4 CRM Configuration

A numerical study of the influence of turbulence models is conducted, of which part of the work has been contributed to the 4 AIAA Drag Prediction Workshop (DPW-4). Simulations have been carried out for three wing-body-tail configurations with three horizontal tail incidences and for one tail-off configuration. The computations consist of a grid refinement study and a downwash study with polar calculations to explore the trimmed condition and delta effects. Three turbulence models are used, including the Explicit Algebraic Reynolds Stress Model (EARSM), the k-ω SST model and the Spalart-Allmaras (SA) model. The grid refinement study, for which the flow is attached, shows rather small differences due to different models. The difference is about 10 drag counts between the highest and smallest drag values predicted, respectively, by the EARSM and the SA model. The polar calculations in the downwash study show also rather small differences, in which the same tendency for the drag prediction is observed as in the grid refinement study. The largest differences between the solutions due to different models are observed at the highest angles of attack, where the flow starts to separate after the shock on the wing.