A Strategy for RANS Turbulence Model Improvement

The vision and final goal of DLR’s guiding concept of a virtual aircraft is the highly accurate numerical and digital modelling of an aircraft with all its properties and components. This requires the development and maturation of highly accurate, cost-effective computing methods including simulation methods for external aerodynamic flows. On the one hand, the related flow regimes are characterized by very high Reynolds numbers. On the other hand, the design and optimization of an aircraft at full coverage of the flight envelope requires an extremely large number of simulations. Hence, the only cost-effective way of doing computational flow simulations is to apply the Reynolds Averaged Navier-Stokes (RANS) equations and the related RANS turbulence models. State-of-the-art RANS turbulence models are an integrated part of wing design for cruise flight, but reliability and maturity for computational flow simulations towards the borders of the flight envelope has not yet been achieved, for example, for the high-lift flow regime. The presentation will give an overview of the activities at the C²A²S²E department at DLR in terms of improving RANS turbulence models and understanding certain flow phenomena in high detail for flow simulations towards the borders of the flight envelope based on experimental and numerical high-fidelity data