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A NON-DISSIPATIVE DYNAMIC SUBGRID SCALE SIMILARITY MODEL

Claus Wagner
German Aerospace Center (DLR), Institute for Aerodynamics and Flow Technology, Bunsenstrasse 10, 37073 Göttingen, Germany; Ilmenau University of Technology, Institute of Thermodynamics and Fluid Mechanics, Germany

Resumo

Two new subgrid scale turbulence models are proposed. The first one is an extension of the classical structure function model. It is shown, that the modified structure function model can be used in Germano's dynamic process (Germano 1992). The second model utilizes a given scale similarity ansatz, which models the subgrid scale stresses in terms of resolved stresses and determines the scaling parameter assuming assuming scale invariance of an eddy-viscosity model. The performance of the derived subgrid scale models has been tested in fully developed turbulent channel flow at low Reynolds number (based on the channel height H and friction velocity uτ) of Re = 360. The same flow was computed by means of underresolved direct numerical simulation (DNS) without model and LES with a dynamic Smagorinsky model. First and second order statistics of the statistically averaged flow field generated in LES using the scale similarity model agree well with DNS data by Kim et al. (Kim 1987).