A Split-Form Discontinuous Galerkin Spectral Element Framework for Scale-Resolving Simulations of Turbomachinery Flows

Abstract

This thesis presents the development of an efficient framework for scale-resolving simulations of turbomachinery configurations within DLR's CFD solver TRACE, utilizing the high-order Discontinuous Galerkin Spectral Element Method (DGSEM). After the validation on resolved canonical flows, a stabilization technique for under-resolved simulations of turbulent flows based on split formulations of the nonlinear flux terms is introduced and compared to state-of-the-art stabilization methods on large eddy simulations (LES) of canonical flows and a low-pressure turbine cascade. Efficiency-driven comparisons between the high-order DGSEM solver and a state-of-the-art LES approach, based on a second-order Finite Volume scheme, demonstrate superior resolution capabilities and performance improvements. The DGSEM solver is extended to simulate unsteady blade interactions, showcasing promising agreement with experimental data of a low-pressure turbine cascade under periodic wake influence.