CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Running, Solving & CFD

OpenFoam validation

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   July 7, 2009, 05:56
Unhappy OpenFoam validation
  #1
New Member
 
qqj
Join Date: Jun 2009
Posts: 12
Rep Power: 8
ranas is on a distinguished road
Hi,

I am validating OpenFOAM on a static 2-D cylinder at Re=200. The radius of the cylinder is 0.5m. The velocity of incoming flow is 1m/s. Mu equals to 0.005.

The full grid is shown here:

grid

I used the following schemes:
ddtSchemes
{
default CrankNicholson 0.5;
}
gradSchemes
{
default Gauss linear;
grad(p) Gauss linear;
}
divSchemes
{
default none;
div(phi,U) Gauss linear;
}
laplacianSchemes
{
default none;
laplacian(nu,U) Gauss linear corrected;
laplacian(1|A(U),p) Gauss linear corrected;
}
interpolationSchemes
{
default linear;
interpolate(HbyA) linear;
}
snGradSchemes
{
default corrected;
}
fluxRequired
{
default no;
p;
}

The standard ICCG and BICCG solvers are used untill convergence to resectively 1e-6 and 1e-5 is obtained. The time step was chosen to be 0.01.

Also the standard boundary conditions are applied:
inlet: U fixed and zeroGradient for p
outlet: p fixed and zeroGradient for U
upper/lower boundary: zeroGradient for p and for U

forceCoeffs
{
type forceCoeffs;
functionObjectLibs ("libforces.so");
patches (circle); //change to your patch name
rhoInf 1;
CofR (0 0 0);
liftDir (0 1 0);
dragDir (1 0 0);
pitchAxis (0 0 0);
magUInf 1;
lRef 1;
Aref 1.0;
}

BrazaM (1985 N um )' result: time average of cd=1. 31; amplitude of cl=0. 65; st=0. 194.
my result: time average of Cd is about 1.9, larger than 1.31; the amplitude of Cl is about 1.0 , more than 0.65; but the st number equals to 0.196 close to the result.

Is someone having any ideas on what's wrong with it? Do I use the proper schemes? Are the bounday conditions correct?

Thanks,
Ranas
ranas is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Superlinear speedup in OpenFOAM 13 msrinath80 OpenFOAM Running, Solving & CFD 18 March 3, 2015 06:36
Modified OpenFOAM Forum Structure and New Mailing-List pete Site News & Announcements 0 June 29, 2009 05:56
64bitrhel5 OF installation instructions mirko OpenFOAM Installation 2 August 12, 2008 18:07
Adventure of fisrst openfoam installation on Ubuntu 710 jussi OpenFOAM Installation 0 April 24, 2008 14:25
OpenFOAM Debian packaging current status problems and TODOs oseen OpenFOAM Installation 9 August 26, 2007 13:50


All times are GMT -4. The time now is 15:34.