CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Pre-Processing

Measure forces on wall with interFoam

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   November 5, 2012, 09:20
Default Measure forces on wall with interFoam
  #1
Member
 
Anon
Join Date: Oct 2012
Posts: 33
Rep Power: 13
jrrygg is on a distinguished road
Hi,

I'm working on a case where I want to measure the force from a nozzle on a wall. I think I know how to get the output, but I don't know how to exactly specify the transportProperties.

I have a quadratic domain with a symmetryplane in the bottom. The nozzle has an inlet of water in the bottom left corner, hitting the wall on the right side of the domain and deflecting the flow upwards along the wall and out of the domain. The rest of the domain consists of water.

I only want to measure the forces from the water beam on the wall. However, if I don't do anything special with the transportProperties interFoam gives me an error message of not having specified nu.

My controlDict script:
Code:
forces
{
type forces;
enabled		false;
functionObjectLibs ("libforces.so"); //Lib to load
patches (backWall);                  // change to your patch name
pName p;
UName U;
rhoName rhoInf;
rhoInf 1000;                          //Reference density for fluid
CofR (0 0 0);                        //Origin for moment calculations
outputControl timeStep;
outputInterval 1;
}

forceCoeffs
{
type forceCoeffs;
enabled 	true;
functionObjectLibs ("libforces.so");
patches (backWall);                  //change to your patch name
pName p;
UName U;
rhoName rhoInf;
rhoInf 1000;
CofR (0 0 0);
liftDir (0 1 0);
dragDir (1 0 0);
pitchAxis (0.5 0.010 0.0005);
magUInf 10;
lRef 1;
Aref 1;
outputControl timeStep;
outputInterval 1;
}
My transportProperties:
Code:
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "constant";
    object      transportProperties;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //


phase1
{
    transportModel  Newtonian;
    nu              nu [ 0 2 -1 0 0 0 0 ] 1e-06;
    rho             rho [ 1 -3 0 0 0 0 0 ] 1000;
    CrossPowerLawCoeffs
    {
        nu0             nu0 [ 0 2 -1 0 0 0 0 ] 1e-06;
        nuInf           nuInf [ 0 2 -1 0 0 0 0 ] 1e-06;
        m               m [ 0 0 1 0 0 0 0 ] 1;
        n               n [ 0 0 0 0 0 0 0 ] 0;
    }

    BirdCarreauCoeffs
    {
        nu0             nu0 [ 0 2 -1 0 0 0 0 ] 0.0142515;
        nuInf           nuInf [ 0 2 -1 0 0 0 0 ] 1e-06;
        k               k [ 0 0 1 0 0 0 0 ] 99.6;
        n               n [ 0 0 0 0 0 0 0 ] 0.1003;
    }
}

phase2
{
    transportModel  Newtonian;
    nu              nu [ 0 2 -1 0 0 0 0 ] 1.48e-05;
    rho             rho [ 1 -3 0 0 0 0 0 ] 1;
    CrossPowerLawCoeffs
    {
        nu0             nu0 [ 0 2 -1 0 0 0 0 ] 1e-06;
        nuInf           nuInf [ 0 2 -1 0 0 0 0 ] 1e-06;
        m               m [ 0 0 1 0 0 0 0 ] 1;
        n               n [ 0 0 0 0 0 0 0 ] 0;
    }

    BirdCarreauCoeffs
    {
        nu0             nu0 [ 0 2 -1 0 0 0 0 ] 0.0142515;
        nuInf           nuInf [ 0 2 -1 0 0 0 0 ] 1e-06;
        k               k [ 0 0 1 0 0 0 0 ] 99.6;
        n               n [ 0 0 0 0 0 0 0 ] 0.1003;
    }
}

sigma           sigma [ 1 0 -2 0 0 0 0 ] 0.07;
I have found that I can run interFoam and get an output if I add
Code:
nu              nu [ 0 2 -1 0 0 0 0 ] 1e-06;
to the start of transportProperties, but won't this give me a wrong value for my air phase?
jrrygg is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
[mesh manipulation] mergeMeshes problem Attesz OpenFOAM Meshing & Mesh Conversion 3 July 29, 2015 05:15
how to get forces on Iso-Clip Surfaces and How to get forces in cylindrical coordinat CFD XUE FLUENT 3 March 18, 2015 04:28
Thin Wall Heat Transfer BC for rhoSimpleFoam swahono OpenFOAM Running, Solving & CFD 12 October 4, 2013 12:49
Patches for OpenFOAM 1.7 on MacOS X gschaider OpenFOAM Installation 101 September 21, 2011 06:37
Wall functions Abhijit Tilak Main CFD Forum 6 February 5, 1999 02:16


All times are GMT -4. The time now is 07:52.