A dynamic mixed subgrid-scale model for large eddy simulation on unstructured grids: application to turbulent pipe flows

31st UIT (Italian Union of Thermo-fluid-dynamics) Heat Transfer Conference 2013

Lampitella, P.^1 ; Colombo, E.^1 ; Inzoli, F.^1

Department of Energy, Politecnico di Milano, Via Lambruschini 4, 20156 Milan, Italy^1

关键词: Classical model;    Dynamic mixed model;    Eddy viscosity;    Numerical tests;    Sub-grid scale models;    Subgrid scale stress;    Turbulent pipe flow;    Unstructured grid;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/501/1/012020/pdf
DOI  :  10.1088/1742-6596/501/1/012020

来源: IOP

【 摘 要 】

The paper presents a consistent large eddy simulation (LES) framework which is particularly suited for implicitly filtered LES with unstructured finite volume (FV) codes. From the analysis of the subgrid-scale (SGS) stress tensor arising in this new LES formulation, a novel form of scale-similar SGS model is proposed and combined with a classical eddy viscosity term. The constants in the resulting mixed model are then computed trough a new, cheaper, dynamic procedure based on a consistent redefinition of the Germano identity within the new LES framework. The dynamic mixed model is implemented in a commercial, unstructured, finite volume solver and numerical tests are performed on the turbulent pipe flow at Reτ320-1142, showing the flexibility and improvements of the approach over classical modeling strategies. Some limitations of the proposed implementation are also highlighted.