DEVELOPMENT OF A 3D COMPRESSIBLE NAVIER-STOKES SOLVER BASED ON A DG FORMULATION WITH SUB-CELL SHOCK CAPTURING STRATEGY FOR FULLY HYBRID UNSTRUCTURED MESHES

The development of a CFD tool based on Discontinuous Galerkin discretization is reported. This tool solves the compressible, Reynolds-Averaged Navier-Stokes equations for three-dimensional, hybrid unstructured meshes. This tool is aimed at complex aerospace ap- plications, thus requiring advanced turbulence models and an efficient numerical framework to enhance computational performance and numerical accuracy for high Reynolds number, high Mach number flows. Inviscid fluxes are computed by upwind Roe or HLLC schemes and viscous fluxes are computed using BR1 or BR2 formulations. A 2nd-order accurate, 5- stage, explicit Runge-Kutta time-stepping scheme is used to march the equations in time. The solver computational efficiency, convergence, accuracy and parallel scalability are addressed through flow simulations over typical validation test cases. Convergence rates for increas- ing degrees of freedom are shown to be asymptotic, with numerical errors compatible to DG schemes. Parallelism is shown to be conformant with the expected scalability behaviour. For the aerospace applications considered in this paper, acceptable agreement with theoretical or experimental results is obtained at adequate computational costs.