Sensitivity Analysis and Multiobjective Optimization for LES Numerical Parameters

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
J.-C. Jouhaud ◽  
P. Sagaut ◽  
B. Enaux ◽  
J. Laurenceau
Keyword(s):  
Large Eddy Simulation ◽  
Surrogate Model ◽  
Low Cost ◽  
Linear Interpolation ◽  
Industrial Applications ◽  
Small Subset ◽  
Eddy Simulation ◽  
Subgrid Model ◽  
Large Eddy ◽  
Optimal Linear

Accuracy and reliability of large-eddy simulation data in a really complex industrial geometry are invesigated. An original methodology based on a response surface for LES data is introduced. This surrogate model for the full LES problem is built using the Kriging technique, which enables a low-cost optimal linear interpolation of a restricted set of large-eddy simulation (LES) solutions. Therefore, it can be used in most realistic industrial applications. Using this surrogate model, it is shown that (i) optimal sets of simulation parameters (subgrid model constant and artificial viscosity parameter in the present case) can be found; (ii) optimal values, as expected, depend on the cost functional to be minimized. Here, a realistic approach, which takes into account experimental data sparseness, is introduced. It is observed that minimization of the error evaluated using a too small subset of reference data may yield a global deterioration of the results.

scholarly journals Adaptation of Phase-Lagged Boundary Conditions to Large Eddy Simulation in Turbomachinery Configurations

2015 ◽  
Vol 138 (4) ◽  
Author(s):  
Gaelle Mouret ◽  
Nicolas Gourdain ◽  
Lionel Castillon
Keyword(s):  
Large Eddy Simulation ◽  
Industrial Applications ◽  
Orthogonal Decomposition ◽  
Navier Stokes ◽  
Compression Method ◽  
Promising Technique ◽  
Computing Power ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Proper Orthogonal

With the increase in computing power, large eddy simulation (LES) emerges as a promising technique to improve both knowledge of complex physics and reliability of turbomachinery flow predictions. However, these simulations are very expensive for industrial applications, especially when a 360  deg configuration should be considered. The objective of this paper is thus to adapt the well-known phase-lagged conditions to the LES approach by replacing the traditional Fourier series decomposition (FSD) with a compression method that does not make any assumptions on the spectrum of the flow. Several methods are reviewed, and the proper orthogonal decomposition (POD) is retained. This new method is first validated on a flow around a circular cylinder with rotating downstream blocks. The results show significant improvements with respect to the FSD. It is then applied to unsteady Reynolds-averaged Navier–Stokes (URANS) simulations of a single-stage compressor in 2.5D and 3D as a first validation step toward single-passage LES of turbomachinery configuration.

scholarly journals Scalar dispersion by a large-eddy simulation and a Lagrangian stochastic subgrid model

2006 ◽  
Vol 18 (9) ◽  
pp. 095101 ◽  
Author(s):  
Guoxin Wei ◽  
Ivana Vinkovic ◽  
Liang Shao ◽  
Serge Simoëns
Keyword(s):  
Large Eddy Simulation ◽  
Scalar Dispersion ◽  
Eddy Simulation ◽  
Subgrid Model ◽  
Large Eddy

Numerical Simulation of an Oscillating Cylinder Using Large Eddy Simulation and Implicit Large Eddy Simulation

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
A. Feymark ◽  
N. Alin ◽  
R. Bensow ◽  
C. Fureby
Keyword(s):  
Large Eddy Simulation ◽  
Eddy Simulation ◽  
Force Magnitude ◽  
Subgrid Model ◽  
Large Eddy ◽  
Sinusoidal Oscillations ◽  
Flow Induced Vibrations ◽  
Lift And Drag ◽  
Implicit And Explicit ◽  
Volume Method

In this work, we use large eddy simulation (LES) to study the influence of grid and subgrid model on the lift and drag force predictions of a fixed cylinder undergoing streamwise sinusoidal oscillations in a steady flow, resulting in a varying Reynolds number, Re, within the range 405 ≤ Re ≤ 2482. This benchmark case is a first step toward studying engineering applications related to flow-induced vibrations. We examine the influence of both grid resolution and the subgrid model using implicit and explicit LES. The methodology used, LES based on a finite-volume method capable of handling moving meshes, are found to provide force predictions that agree well with experimentally measured data, with respect both to the overall flow development and force magnitude.

Aspects of subgrid modelling and large-eddy simulation of magnetohydrodynamic turbulence

1991 ◽  
Vol 45 (2) ◽  
pp. 239-249 ◽  
Author(s):  
Ye Zhou ◽  
George Vahala
Keyword(s):  
Large Eddy Simulation ◽  
Subgrid Scale ◽  
Dynamo Theory ◽  
Mhd Turbulence ◽  
Eddy Simulation ◽  
Subgrid Model ◽  
Large Eddy ◽  
Reversed Field ◽  
Filtering Technique ◽  
Incompressible Mhd

Subgrid-scale closures for magnetohydodynamic (MHD) turbulence are examined using the filtering technique. From the similarities between incompressible MHD turbulence and its hydrodynamic counterpart, as well as ideas from dynamo theory, a subgrid model is constructed from the large-eddy simulation (LES) of MHD turbulence. This model should find applicability in treating LES of the reversed-field pinch.

scholarly journals An Overview of Hybrid RANS–LES Models Developed for Industrial CFD

2021 ◽  
Vol 11 (6) ◽  
pp. 2459
Author(s):  
Florian Menter ◽  
Andreas Hüppe ◽  
Alexey Matyushenko ◽  
Dmitry Kolmogorov
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Large Eddy Simulation ◽  
Boundary Layers ◽  
Shear Flows ◽  
Low Cost ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Computational Fluid Dynamics Cfd

An overview of scale-resolving simulation (SRS) methods used in ANSYS Computational Fluid Dynamics (CFD) software is provided. The main challenges, especially when computing boundary layers in large eddy simulation (LES) mode, will be discussed. The different strategies for handling wall-bound flows using combinations of RANS and LES models will be explained, along with some specific application examples. It will be demonstrated that the stress-blended eddy simulation (SBES) approach is optimal for applications with a mix of boundary layers and free shear flows due to its low cost and its ability to handle boundary layers in both RANS and wall-modeled LES (WMLES) modes.

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