Scale-Resolving Simulations on Unstructured Meshes with a Low-Dissipation Low-Dispersion Scheme

Kurzfassung

Introduction Scale-resolving simulations such as hybrid RANS/LES methods (HRLM) are considered as promising approaches for improved numerical predictions of aeronautical flows near the boarder of the flight envelope. Due to the requirement to locally resolve turbulent fluctua-tions, these methods rely on an accurate spatial discretization, both in terms of the grid reso-lution and the numerical scheme for the flow equations. For this reason, most scale-resolving flow solvers apply structured grid metrics, which provide regular mesh cells and allow for rather easy implementation of higher-order schemes. However, with the increasing demand for simulations of complex geometries, e.g., high-lift wings with brackets and in-stalled engines, the generation of purely structured grids becomes infeasible and is often abandoned in favour of unstructured methods, such as the widely-used DLR-TAU code. To qualify the TAU code for accurate scale-resolving simulations, a low-dissipation low-dispersion (LD2) scheme suitable for unstructured solvers has recently been developed [1]. While the LD2-scheme has already been shown to improve HRLM predictions on structured grids [2], the present work comprises first systematic studies on the applicability and accura-cy of the LD2-scheme on industry-relevant unstructured or hybrid grids.