We assess the performance of a high-order discontinuous Galerkin (DG) approach to simulate wall-bounded turbulent flows for a range of Reynolds numbers. First, a plane channel flow configuration with turbulent heat transfer at Re τ = 640 is considered. Second, a detached flow configuration is investigated. This configuration represents the flow over periodically arranged hills. Four bulk Reynolds numbers Re b are considered: 2 800, 10 595, 19 000, and 37 000. For Re b = 2 800 direct numerical simulation (DNS) is used. Large-eddy simulations (LES) based on the WALE subgrid-scale model are carried out for the higher Re b . The simulation results are compared to reference data from CFD and experiment. hp-convergence analyses are performed which demonstrate the superior performance of increasing the polynomial order as compared to refining the mesh. It appears from this work that the use of a subgrid modelling approach together with local hp-adaptation could greatly improve the accuracy of the solution without penalising the computational cost of the simulation.

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A new fully integrated environment for compressible flow simulation on structured and unstructured zones coexisting within the same hybrid mesh is presented. This environment originates from the existing elsA a CFD software tool, developed by ONERA and CERFACS for structured grids, and widely used both in industry and research.Some configurations can not be easily addressed with a fully structured mesh approach. An efficient way to overcome this drawback is to combine structured and unstructured zones in a single hybrid mesh. Structured zones are kept for sake of accuracy in boundary layers, wall clock efficiency and low memory consumption. Unstructured zones enable an easier mesh generation / adaptation process. This paper describes the extension of elsA to unstructured multi-element zones composed of hexahedra, tetrahedra, prisms and pyramids. A key feature is the treatment of structured / unstructured zone interfaces, performed with a mismatched abutting grid interface algorithm.We demonstrate that the Object-Oriented (OO) programming approach is useful and efficient to integrate unstructured data structures and numerical methods into the original software to form a single computational CFD kernel.Software design, numerical algorithm, structured/unstructured block interface treatment, CPU efficiency and parallel scalability, are discussed. Finally, validation examples demonstrating the project status are given.

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