Application of SST-Based SLA-DDES Formulation to Turbomachinery Flows

In turbomachinery CFD simulations, Reynolds-Averaged Navier-Stokes (RANS) based approaches tend to under-predict turbulent mixing, which is of particular importance in the endwall region. Detached Eddy Simulation (DES), solving Reynolds-averaged equations near the wall and partially resolving turbulent content elsewhere, bypasses the difficulties in statistic modeling. Previous work using Delayed-DES (DDES) in a linear compressor cascade [6] showed improved loss profile prediction owing to better representation of flow structures. The observation was that certain grid refinement near separated shear layer is necessary for resolving unsteadiness and further more, to reveal a bimodal behavior of the separation. Recent development in DES, the Shear-Layer-Adapted (SLA) modification [5], is designed to accelerate the growth of resolved turbulence downstream of the RANS-to-LES interface. In the current work, the impact of SLA modification on the DES simulation of linear compressor cascade flow is investigated. We incorporated the SLA modification into the SST-DDES [7] model and quantified the benefit of it in turbomachinery applications.