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15 mins
Building proper invariants for subgrid-scale eddy-viscosity models
F.Xavier Trias, David Folch, Andrey Gorobets, Assensi Oliva
Session: Large Eddy Simulation 3
Session starts: Friday 28 August, 10:30
Presentation starts: 12:00
Room: Room E

F.Xavier Trias (Technical University of Catalonia)
David Folch (Technical University of Catalonia)
Andrey Gorobets (Keldysh Institute of Applied Mathematics)
Assensi Oliva (Technical University of Catalonia)

Since direct simulations of the incompressible Navier-Stokes equations are limited to relatively low-Reynolds numbers, dynamically less complex mathematical formulations are necessary for coarse-grain simulations. Eddy-viscosity models for Large-Eddy Simulation is probably the most popular example thereof: they rely on differential operators that should be able to capture well different flow configurations (laminar and 2D flows, near-wall behavior, transitional regime...). Most of them are based on the combination of invariants of a symmetric second-order tensor that is derived from the gradient of the resolved velocity field. In the present work, they are presented in a framework where all the models are represented as a combination of elements of a 5D phase space of invariants. In this way, new models can be constructed by imposing appropriate restrictions in this space. The performance of the proposed models is successfully tested for a turbulent channel flow.