Large Eddy Simulations Using the Subgrid-Scale Estimation Model and Truncated Navier-Stokes Dynamics

2001 ◽  
pp. 45-54 ◽  
Author(s):  
J. A. Domaradzki ◽  
K. C. Loh ◽  
P. P. Yee
Keyword(s):  
Large Eddy Simulations ◽  
Navier Stokes ◽  
Subgrid Scale ◽  
Estimation Model ◽  
Scale Estimation ◽  
Large Eddy

The subgrid-scale estimation model applied to large eddy simulations of compressible turbulence

2002 ◽  
Vol 14 (5) ◽  
pp. 1781-1801 ◽  
Author(s):  
Thierry Dubois ◽  
J. A. Domaradzki ◽  
Albert Honein
Keyword(s):  
Large Eddy Simulations ◽  
Compressible Turbulence ◽  
Subgrid Scale ◽  
Estimation Model ◽  
Scale Estimation ◽  
Large Eddy

Effective Subgrid Modeling From the ILES Simulation of Compressible Turbulence

2007 ◽  
Vol 129 (12) ◽  
pp. 1493-1496 ◽  
Author(s):  
William J. Rider
Keyword(s):  
Incompressible Flows ◽  
Stokes Equations ◽  
Standard Form ◽  
Large Eddy Simulations ◽  
Compressible Turbulence ◽  
Navier Stokes ◽  
Subgrid Scale ◽  
Self Similarity ◽  
Large Eddy ◽  
Similarity Model

Implicit large eddy simulation (ILES) has provided many computer simulations with an efficient and effective model for turbulence. The capacity for ILES has been shown to arise from a broad class of numerical methods with specific properties producing nonoscillatory solutions using limiters that provide these methods with nonlinear stability. The use of modified equation has allowed us to understand the mechanisms behind the efficacy of ILES as a model. Much of the understanding of the ILES modeling has proceeded in the realm of incompressible flows. Here, we extend this analysis to compressible flows. While the general conclusions are consistent with our previous findings, the compressible case has several important distinctions. Like the incompressible analysis, the ILES of compressible flow is dominated by an effective self-similarity model (Bardina, J., Ferziger, J. H., and Reynolds, W. C., 1980, “Improved Subgrid Scale Models for Large Eddy Simulations,” AIAA Paper No. 80–1357; Borue, V., and Orszag, S. A., 1998, “Local Energy Flux and Subgrid-Scale Statistics in Three Dimensional Turbulence,” J. Fluid Mech., 366, pp. 1–31; Meneveau, C., and Katz, J., 2000, “Scale-Invariance and Turbulence Models for Large-Eddy Simulations,” Annu. Rev. Fluid. Mech., 32, pp. 1–32). Here, we focus on one of these issues, the form of the effective subgrid model for the conservation of mass equations. In the mass equation, the leading order model is a self-similarity model acting on the joint gradients of density and velocity. The dissipative ILES model results from the limiter and upwind differencing resulting in effects proportional to the acoustic modes in the flow as well as the convective effects. We examine the model in several limits including the incompressible limit. This equation differs from the standard form found in the classical Navier–Stokes equations, but generally follows the form suggested by Brenner (2005, “Navier-Stokes Revisited,” Physica A, 349(1–2), pp. 60–133) in a modification of Navier–Stokes necessary to successfully reproduce some experimentally measured phenomena. The implications of these developments are discussed in relation to the usual turbulence modeling approaches.

LES Validation for a Rotating Cylindrical Cavity With Radial Inflow

2016 ◽  
Author(s):  
Michel Onori ◽  
Dario Amirante ◽  
Nicholas J. Hills ◽  
John W. Chew
Keyword(s):  
Boundary Layers ◽  
Source Region ◽  
Tangential Velocity ◽  
Large Eddy Simulations ◽  
Navier Stokes ◽  
Subgrid Scale ◽  
Rotating Cavity ◽  
Scale Models ◽  
Large Eddy ◽  
Type Boundary

This paper describes Large-Eddy Simulations (LES) of the flow in a rotating cavity with narrow inter-disc spacing and a radial inflow introduced from the shroud. Simulations have been conducted using a compressible, unstructured, finite-volume solver, and testing different subgrid scale models. These include the standard Smagorinsky model with Van Driest damping function near the wall, the WALE model and the implicit LES procedure. Reynolds averaged Navier-Stokes (RANS) results, based on the Spalart-Allmaras and SST k-ω models, are also presented. LES solutions reveal a turbulent source region, a laminar oscillating core with almost zero axial and radial velocity and turbulent Ekman type boundary layers along the discs. Validations are carried out against the experimental data available from the study of Firouzian et al. [1]. It is shown that the tangential velocity and the pressure drop across the cavity are very well predicted by both RANS and LES, although significant differences are observed in the velocity profiles within the boundary layers.

Subgrid-scale models for large-eddy simulations of compressible wall bounded flows

AIAA Journal ◽  
2000 ◽  
Vol 38 ◽  
pp. 1340-1350 ◽  
Author(s):  
E. Lenormand ◽  
P. Sagaut ◽  
L. Ta Phuoc ◽  
P. Comte
Keyword(s):  
Large Eddy Simulations ◽  
Subgrid Scale ◽  
Scale Models ◽  
Large Eddy ◽  
Wall Bounded Flows

scholarly journals Statistical ensemble of large-eddy simulations

2002 ◽  
Vol 455 ◽  
pp. 195-212 ◽  
Author(s):  
DANIELE CARATI ◽  
MICHAEL M. ROGERS ◽  
ALAN A. WRAY
Keyword(s):  
Large Scale ◽  
Isotropic Turbulence ◽  
Velocity Fields ◽  
Large Eddy Simulations ◽  
Statistical Ensemble ◽  
Model Parameters ◽  
Spatial Averaging ◽  
Subgrid Scale ◽  
Large Eddy ◽  
New Models

A statistical ensemble of large-eddy simulations (LES) is run simultaneously for the same flow. The information provided by the different large-scale velocity fields is used in an ensemble-averaged version of the dynamic model. This produces local model parameters that only depend on the statistical properties of the flow. An important property of the ensemble-averaged dynamic procedure is that it does not require any spatial averaging and can thus be used in fully inhomogeneous flows. Also, the ensemble of LES provides statistics of the large-scale velocity that can be used for building new models for the subgrid-scale stress tensor. The ensemble-averaged dynamic procedure has been implemented with various models for three flows: decaying isotropic turbulence, forced isotropic turbulence, and the time-developing plane wake. It is found that the results are almost independent of the number of LES in the statistical ensemble provided that the ensemble contains at least 16 realizations.

Disruption of the bottom log layer in large-eddy simulations of full-depth Langmuir circulation

2012 ◽  
Vol 699 ◽  
pp. 79-93 ◽  
Author(s):  
A. E. Tejada-Martínez ◽  
C. E. Grosch ◽  
N. Sinha ◽  
C. Akan ◽  
G. Martinat
Keyword(s):  
Gravity Waves ◽  
Large Eddy Simulations ◽  
Stokes Drift ◽  
Navier Stokes ◽  
Wake Region ◽  
Langmuir Circulation ◽  
Mean Velocity ◽  
Wave Forcing ◽  
Large Eddy ◽  
Shear Current

AbstractWe report on disruption of the log layer in the resolved bottom boundary layer in large-eddy simulations (LES) of full-depth Langmuir circulation (LC) in a wind-driven shear current in neutrally-stratified shallow water. LC consists of parallel counter-rotating vortices that are aligned roughly in the direction of the wind and are generated by the interaction of the wind-driven shear with the Stokes drift velocity induced by surface gravity waves. The disruption is analysed in terms of mean velocity, budgets of turbulent kinetic energy (TKE) and budgets of TKE components. For example, in terms of mean velocity, the mixing due to LC induces a large wake region eroding the classical log-law profile within the range $90\lt { x}_{3}^{+ } \lt 200$. The dependence of this disruption on wind and wave forcing conditions is investigated. Results indicate that the amount of disruption is primarily determined by the wavelength of the surface waves generating LC. These results have important implications for turbulence parameterizations for Reynolds-averaged Navier–Stokes simulations of the coastal ocean.

Neural networks based subgrid scale modeling in large eddy simulations

2003 ◽  
Vol 32 (1) ◽  
pp. 97-108 ◽  
Author(s):  
F. Sarghini ◽  
G. de Felice ◽  
S. Santini
Keyword(s):  
Neural Networks ◽  
Large Eddy Simulations ◽  
Subgrid Scale ◽  
Scale Modeling ◽  
Large Eddy ◽  
Subgrid Scale Modeling

Subgrid scale variance and dissipation of a scalar field in large eddy simulations

2001 ◽  
Vol 13 (6) ◽  
pp. 1748-1754 ◽  
Author(s):  
C. Jiménez ◽  
F. Ducros ◽  
B. Cuenot ◽  
B. Bédat
Keyword(s):  
Scalar Field ◽  
Large Eddy Simulations ◽  
Subgrid Scale ◽  
Large Eddy
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