A new multiscale model with proper behaviour in both vortex flows and wall bounded flows
(2010) Seventh International ERCOFTAC Workshop on Direct and Large-Eddy Simulation — Location: University of Trieste (8.September.2008)
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- A new subgrid-scale (SGS) model which has an adequate behaviour in both vortical flows and wall-bounded flows is proposed. In wall-bounded flows computed using wall-resolved LES, the theory predicts that the SGS dissipation should vanish with a y +3 behaviour near the wall. In the case of vortex flows, one needs to have models which do not dissipate energy in the strongly vortical and essentially laminar part of the flow, e.g. in vortex core regions. The model presented here aims at combining the strengths of two models as it is a regularized variational multiscale (RVM) model (as in Jeanmart and Winckelmans [3]), thus acting on the high pass filtered LES field, and for which the subgrid-scale viscosity is evaluated using the WALE (wall adapting local eddy viscosity) scaling of Nicoud and Ducros [5], itself computed using the high pass filtered LES field. Thus this model is only active when there is a significant high wavenumber content in the flow and it has a natural near wall damping behaviour. The ability of this model to simulate vortex and wall-bounded flows is demonstrated on three test cases. The first case is the turbulent channel flow. The second case concerns a four-vortex system. The third case concerns a two-vortex system in ground effect. It is shown that this new model allows to perform successfully LES of these flows with the proper dissipative behaviour in both near wall and vortical regions. The LES are performed using a parallel fourth order code based on finite differences.
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Bricteux, L., Duponcheel, M., & Winckelmans, G. (2010). A new multiscale model with proper behaviour in both vortex flows and wall bounded flows. In Vincenzo Armenio, Bernard Geurts and Jochen Fröhlich (ed.), Direct and Large-Eddy Simulation VII (pp. 247-252). https://doi.org/10.1007/978-90-481-3652-0_37