Forces printout for multiple patches
 

Hi all,

I'm trying to print out forces and forcesCoeffs for more than 1 patch and I'm not sure on the syntax that I use in my controlDict file. The case that I have is a simple 2D pipe flow with some bends. I am using my wall friction as a condition for convergence so I need to monitor it as I progress through my iterations. Any help would be greatly appreciated.

Thanks

Hi

e.g.:

forcesA
{
interval 25;
type forces;
functionObjectLibs ("libforces.so"); //Lib to load
patches (vanA); // change to your patch name
rhoName rhoInf;
rhoInf 1.23; //Reference density for fluid
CofR (0 0 0); //Origin for moment calculations
}
forcesB
{
interval 25;
type forces;
functionObjectLibs ("libforces.so"); //Lib to load
patches (vanB); // change to your patch name
rhoName rhoInf;
rhoInf 1.23; //Reference density for fluid
CofR (0 0 0); //Origin for moment calculations
}
forcesC
{
interval 25;
type forces;
functionObjectLibs ("libforces.so"); //Lib to load
patches (vanC); // change to your patch name
rhoName rhoInf;
rhoInf 1.23; //Reference density for fluid
CofR (0 0 0); //Origin for moment calculations
}

Hi Jeff,

I am kind of new in OpenFOAM world; could you please help me know how could I use calculated forces during run time in my solver?
I want to use the calculated forces, but I don't know what I should do.
Thank you.

If you have multiple patches and if you want only the sum of the data (and not the data for each patch), you can use one "forces", e.g.

forces
{
type forces;
functionObjectLibs ("libforces.so");
outputControl timeStep;
outputInterval 1;
patches (patch1 patch2); // change to your patches name
rhoName rhoInf;
log true;
rhoInf 1.205; //Reference density for fluid
CofR (0 0 0); //Origin for moment calculations
}

The sum of the data will be written in the "forces.dat" file

Regards