A parallel high-order discontinuous Galerkin solver applied to complex three-dimensional turbulent flows

This paper deals with the application of a recently developed Reynolds-Averaged Navier-Stokes (RANS) discontinuous finite element solver in the computation of the three dimensional flow field around a film cooled nozzle guide vane. The RANS equations are coupled with the high- or low-Reynolds number k-ω turbulence model. A non-standard implementation of the k-ω model, whereby the logarithm of omega rather than omega itself is used as unknown, has been found very useful to enhance the stability of the method. Robustness and efficiency of the code have been further improved by satisfying realizability constraints and Schwarz inequality on turbulent stresses. The solver uses explicit and implicit time stepping schemes, can employ arbitrary unstructured hybrid grids, and has been fully parallelized using message passing as implemented in the PETSc library.