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Evaluation of sub grid scale and local wall models in Large-eddy simulations of separated flow

Al Sam, Ali LU ; Szász, Robert-Zoltán LU and Revstedt, Johan LU (2015) Second Symposium on OpenFOAM® in Wind Energy In 2nd Symposium on OpenFOAM® in Wind Energy 5.
Abstract
The performance of the Sub Grid Scale models is studied by simulating a separated flow over a wavy channel. The first and second order statistical moments of the resolved velocities obtained by using Large-Eddy simulations at different mesh resolutions are compared with Direct Numerical Simulations data. The effectiveness of modeling the wall stresses by using local log-law is then tested on a relatively coarse grid. The results exhibit a good agreement between highly-resolved Large Eddy Simulations and Direct Numerical Simulations data regardless the Sub Grid Scale models. However, the agreement is less satisfactory with relatively coarse grid without using any wall models and the differences between Sub Grid Scale models are... (More)
The performance of the Sub Grid Scale models is studied by simulating a separated flow over a wavy channel. The first and second order statistical moments of the resolved velocities obtained by using Large-Eddy simulations at different mesh resolutions are compared with Direct Numerical Simulations data. The effectiveness of modeling the wall stresses by using local log-law is then tested on a relatively coarse grid. The results exhibit a good agreement between highly-resolved Large Eddy Simulations and Direct Numerical Simulations data regardless the Sub Grid Scale models. However, the agreement is less satisfactory with relatively coarse grid without using any wall models and the differences between Sub Grid Scale models are distinguishable. Using local wall model returned the basic flow topology and reduced significantly the differences between the coarse meshed Large-Eddy Simulations and Direct Numerical Simulations data. The results show that the ability of local wall model to predict the separation zone depends strongly on its implementation way. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
in
2nd Symposium on OpenFOAM® in Wind Energy
editor
J. Churchfield, Matthew
volume
5
pages
11 pages
publisher
E3S Web of Conferences
conference name
Second Symposium on OpenFOAM® in Wind Energy
DOI
10.1051/e3sconf/20150503002
language
English
LU publication?
yes
id
a4f2cb96-ff99-4a1e-981b-7d1c9a158914
date added to LUP
2016-06-29 13:40:18
date last changed
2016-07-04 08:41:56
@misc{a4f2cb96-ff99-4a1e-981b-7d1c9a158914,
  abstract     = {The performance of the Sub Grid Scale models is studied by simulating a separated flow over a wavy channel. The first and second order statistical moments of the resolved velocities obtained by using Large-Eddy simulations at different mesh resolutions are compared with Direct Numerical Simulations data. The effectiveness of modeling the wall stresses by using local log-law is then tested on a relatively coarse grid. The results exhibit a good agreement between highly-resolved Large Eddy Simulations and Direct Numerical Simulations data regardless the Sub Grid Scale models. However, the agreement is less satisfactory with relatively coarse grid without using any wall models and the differences between Sub Grid Scale models are distinguishable. Using local wall model returned the basic flow topology and reduced significantly the differences between the coarse meshed Large-Eddy Simulations and Direct Numerical Simulations data. The results show that the ability of local wall model to predict the separation zone depends strongly on its implementation way.},
  author       = {Al Sam, Ali and Szász, Robert-Zoltán and Revstedt, Johan},
  editor       = {J. Churchfield, Matthew },
  language     = {eng},
  month        = {10},
  pages        = {11},
  publisher    = {ARRAY(0x8c39510)},
  series       = {2nd Symposium on OpenFOAM® in Wind Energy},
  title        = {Evaluation of sub grid scale and local wall models in Large-eddy simulations of separated flow},
  url          = {http://dx.doi.org/10.1051/e3sconf/20150503002},
  volume       = {5},
  year         = {2015},
}