A new dynamic two-parameter mixed model for large-eddy simulation

1997 ◽  
Vol 9 (11) ◽  
pp. 3443-3464 ◽  
Author(s):  
Kiyosi Horiuti
Keyword(s):  
Large Eddy Simulation ◽  
Mixed Model ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Two Parameter

scholarly journals Improving Large-Eddy Simulation of Neutral Boundary Layer Flow across Grid Interfaces

2015 ◽  
Vol 143 (8) ◽  
pp. 3310-3326 ◽  
Author(s):  
Elijah Goodfriend ◽  
Fotini Katopodes Chow ◽  
Marcos Vanella ◽  
Elias Balaras
Keyword(s):  
Boundary Layer ◽  
Large Eddy Simulation ◽  
Atmospheric Boundary Layer ◽  
Adaptive Mesh Refinement ◽  
Mixed Model ◽  
Adaptive Mesh ◽  
Grid Refinement ◽  
Eddy Simulation ◽  
Advection Term ◽  
Large Eddy

Abstract Increasing computational power has enabled grid resolutions that support large-eddy simulation (LES) of the atmospheric boundary layer. These simulations often use grid nesting or adaptive mesh refinement to refine the grid in regions of interest. LES generates errors at grid refinement interfaces, such as resolved energy accumulation, that may compromise solution accuracy. In this paper, the authors test the ability of two LES formulations and turbulence closures to mitigate errors associated with the use of LES on nonuniform grids for a half-channel approximation to a neutral atmospheric boundary layer simulation. Idealized simulations are used to examine flow across coarse–fine and fine–coarse interfaces, as would occur in a two-way nested configuration or with block structured adaptive mesh refinement. Specifically, explicit filtering of the advection term and the mixed model are compared to a standard LES formulation with an eddy viscosity model. Errors due to grid interfaces are evaluated by comparison to uniform grid solutions. It is found that explicitly filtering the advection term provides significant benefits, in that it allows both mass and momentum to be conserved across grid refinement interfaces. The mixed model reduces unphysical perturbations generated by wave reflection at the interfaces. These results suggest that the choice of LES formulation and turbulence closure can be used to help control grid refinement interface errors in atmospheric boundary layer simulations.

A compressible wall-adapting similarity mixed model for large-eddy simulation of the impinging round jet

2009 ◽  
Vol 21 (3) ◽  
pp. 035102 ◽  
Author(s):  
Guido Lodato ◽  
Luc Vervisch ◽  
Pascale Domingo
Keyword(s):  
Large Eddy Simulation ◽  
Mixed Model ◽  
Round Jet ◽  
Eddy Simulation ◽  
Large Eddy

scholarly journals Dynamic Nonlinear Algebraic Models With Scale-Similarity Dynamic Procedure For Large-Eddy Simulation of Turbulence

2021 ◽  
Author(s):  
Zelong Yuan ◽  
Yunpeng Wang ◽  
Chenyue Xie ◽  
Jianchun Wang
Keyword(s):  
Large Eddy Simulation ◽  
Mixed Model ◽  
A Priori ◽  
Correlation Coefficients ◽  
Algebraic Model ◽  
Algebraic Models ◽  
Eddy Simulation ◽  
Turbulent Statistics ◽  
Large Eddy ◽  
Scale Similarity

Abstract A dynamic nonlinear algebraic model with scale-similarity dynamic procedure (DNAM-SSD) is proposed for subgrid-scale (SGS) stress in large-eddy simulation of turbulence. The model coefficients of the DNAM-SSD model are adaptively calculated through the scale-similarity relation, which greatly simplifies the conventional Germano-identity based dynamic procedure (GID). The a priori study shows that the DNAM-SSD model predicts the SGS stress considerably better than the conventional velocity gradient model (VGM), dynamic Smagorinsky model (DSM), dynamic mixed model (DMM) and DNAM-GID model at a variety of filter widths ranging from inertial to viscous ranges. The correlation coefficients of the SGS stress predicted by the DNAM-SSD model can be larger than 95% with the relative errors lower than 30%. In the a posteriori testings of LES, the DNAM-SSD model outperforms the implicit LES (ILES), DSM, DMM and DNAM-GID models without increasing computational costs, which only takes up half the time of the DNAM-GID model. The DNAM-SSD model accurately predicts plenty of turbulent statistics and instantaneous spatial structures in reasonable agreement with the filtered DNS data. These results indicate that the current DNAM-SSD model is attractive for the development of highly accurate SGS models for LES of turbulence.

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