Comparative Assessment of Synthetic Turbulence Methods in an Unstructured Compressible Flow Solver
Three different synthetic turbulence methods are assessed in hybrid RANS/LES simulations with the unstructured compressible flow solver DLR-TAU. Fluctuations computed with either the Synthetic-Eddy Method, its divergence-free version, or the Synthetic-Turbulence Generator are injected via momentum sources into the flow field. In a flat plate flow, the latter method yields minimal deviations from reference data when combined with suited volume forcing, while the induced noise is not larger than in the other methods. In a mixing co-flow, all approaches yield decent predictions of the flow development apart from a slightly too high mixing rate.
KeywordsHybrid RANS/LES Wall-modelled LES Synthetic turbulence Flat plate Mixing co-flow
The STG implementation in TAU including the blending function for variable volume forcing was provided by Daniela G. François, now DLR Göttingen. The mixing co-flow was defined as common test case in the GARTEUR Action Group 54 “RaLESin”.
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