LES model

s-ammarlu · June 7, 2011, 10:55

Hi OpenFOAM, in particular LES players,
I am doing simulation of rectangular channel with fully development turbulent flow, using LES model and oodles solver .
i have given the
velocity at the inlet is 0.2m/s and Re =10,000 , nu=10^-5 . i applied the boundary conditions : velovity inlet
inlet in inlet, and presure outlet in outlet , and wall for walls .
i didnt see any structure of turbulent .
can any one suggest what is the problem for me? whether i have to change any other boundary conditions? please give me reply?

gregor · June 8, 2011, 03:26

hi
especially for LES proper inflow conditions are important. Using a velocity inlet without pertubations wont give you any reasonable turbulence in your domain. You should take a look at http://www.cfd-online.com/Forums/openfoam-solving/77084-turbulence-inflow-generation-recycling-method.html

or

M. Klein, A. Sadiki und J. Janicka A Digital Filter Based Generation of Inflow Data for Spatially Developing Direct Numerical or Large Eddy Simulations. J. Comp. Physics,186:652--665, 2002.

gregor

s-ammarlu · June 8, 2011, 10:19

hi gregor
i want this article , can you please send it or attach it ?
"A digital filter based generation of inflow data for spatially developing direct numerical or large eddy simulations "Journal of Computational Physics, Volume 186, Issue 2, 10 April 2003, Pages 652-665
M. Klein, A. Sadiki and J. Janicka

cheng1988sjtu · June 8, 2011, 12:49

Hi,

I suggest using perterbU utility to add perturbation to the initial condition.

you can search in the forum for this utility.

Good Luck!

Zhen

June 7, 2011, 10:55	LES model	#1
s-ammarlu New Member Join Date: Apr 2011 Posts: 20 Rep Power: 15	Hi OpenFOAM, in particular LES players, I am doing simulation of rectangular channel with fully development turbulent flow, using LES model and oodles solver . i have given the velocity at the inlet is 0.2m/s and Re =10,000 , nu=10^-5 . i applied the boundary conditions : velovity inlet inlet in inlet, and presure outlet in outlet , and wall for walls . i didnt see any structure of turbulent . can any one suggest what is the problem for me? whether i have to change any other boundary conditions? please give me reply?

June 8, 2011, 12:49	perturbU	#4
cheng1988sjtu Member Charlie Join Date: Dec 2010 Location: USA Posts: 85 Rep Power: 15	Hi, I suggest using perterbU utility to add perturbation to the initial condition. you can search in the forum for this utility. Good Luck! Zhen

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
buoyantBoussinesqPisoFoam can't use LES model ?	panda60	OpenFOAM	1	December 30, 2009 17:41
Implementing a new LES Model in OpenFoam	fs82	OpenFOAM	6	October 13, 2009 09:58
help urgent LES model for a swimming pool	marion	FLUENT	0	June 4, 2007 05:26
Anisotropic subgrid model (LES)	h.jordi	Main CFD Forum	1	August 29, 2002 15:49
LES pipe model	Matt	FLUENT	1	August 21, 2002 14:19

June 8, 2011, 03:26		#2
gregor Member Gregor Olenik Join Date: Jun 2009 Location: http://greole.github.io/ Posts: 89 Rep Power: 16	hi especially for LES proper inflow conditions are important. Using a velocity inlet without pertubations wont give you any reasonable turbulence in your domain. You should take a look at http://www.cfd-online.com/Forums/openfoam-solving/77084-turbulence-inflow-generation-recycling-method.html or M. Klein, A. Sadiki und J. Janicka A Digital Filter Based Generation of Inflow Data for Spatially Developing Direct Numerical or Large Eddy Simulations. J. Comp. Physics,186:652--665, 2002. gregor

June 8, 2011, 10:19		#3
s-ammarlu New Member Join Date: Apr 2011 Posts: 20 Rep Power: 15	hi gregor i want this article , can you please send it or attach it ? "A digital filter based generation of inflow data for spatially developing direct numerical or large eddy simulations "Journal of Computational Physics, Volume 186, Issue 2, 10 April 2003, Pages 652-665 M. Klein, A. Sadiki and J. Janicka