OpenFOAM for High-Lift Aerodynamics: Reynolds-Averaged Navier–Stokes Prediction Capabilities

This paper validates OpenFOAM, an open-source computational fluid dynamics (CFD) software, for modeling separated flows relevant to aircraft aerodynamics with high-lift wing configurations. Reynolds-averaged Navier–Stokes (RANS) simulations of flow past the Common Research Model (CRM) in its High-Lift configuration were performed in two stages. The first stage focused on aerodynamic coefficients near the stall angle of attack as part of a grid refinement study, comparing results with those from other participants in the High-Lift Prediction Workshop who used various CFD codes. The second stage validated OpenFOAM against wind-tunnel data and workshop CFD results across a sequential buildup of configuration complexity, from wing–fuselage only to the full configuration including flaps, slats, and engine nacelles with pylons. Particular attention was paid to using RANS modeling in OpenFOAM to obtain multiple flow solutions for high-lift configurations. The results showed that OpenFOAM’s RANS predictions aligned more closely with wind-tunnel data than those of other workshop participants and revealed static hysteresis over a wide range of angles of attack, driven by distinct flow separation structures. These findings encourage the use OpenFOAM for aerodynamics prediction of high-lift configurations and support its growing adoption in both academia and industry.