Unstructured mesh capabilities for supersonic wing design at low speed conditions

Kurzfassung

In this paper the reliability of using unstructured meshes for the CFD simulation of the flow over a low aspect-ratio wing in low speed configuration is investigated. It is intended to integrate such mesh strategy in a high-fidelity aerodynamic shape optimization loop for the design of high lift devices, so particular care is given to the set-up of a suitable meshing procedure usable in optimization context. Meshes are created using the grid generators Solar and Centaur; the CFD analysis is carried out using the DLR-TAU solver on the EPISTLE wing-body configuration with drop-nose slat. Results are compared to wind tunnel test data and to CFD results obtained on a structured mesh. It is shown that a grid of around 10 million points, if carefully conceived, is able to predict with reasonably good accuracy the aerodynamic loads and the overall flow features. Some discrepancies in the detection of vortical flow features are found, but they do not have significant influence on the computed loads. The application of the method at various Reynolds numbers confirms the importance of the prismatic layer thickness to accurately capture the vortical flow features.