[czhongrong]

I've run my simulations and I want to extract the Cd values for my cylinder.

1) I added the following function block in my controlDict (same template which I found online).

forces
{
type forces;
functionObjectLibs ("libforces.so"); //Lib to load
patches (cylinder);
pName p;
UName U;
log true;
rhoName rhoInf;
rhoInf 1; //Reference density for fluid
CofR (0 0 0);
outputControl timeStep;
outputInterval 1;
}

forceCoeffs
{
type forceCoeffs;
functionObjectLibs ("libforces.so");
outputControl timeStep;
outputInterval 1;
patches (cylinder);
pName p;
UName U;
log true;
rhoName rhoInf;
rhoInf 1;
CofR (0 0 0);
liftDir (0 1 0);
dragDir (1 0 0);
pitchAxis (0 1 0);
magUInf 1;//reference velocity
lRef 1;//reference length to calculate moment coefficient
Aref 1;//*****Modification is required when the mesh is changed.
}

2) I open the forceCoeffs.dat file and extract the long list of Cd values.

3) I took the average of all the values and I am getting Cd values in the range of 16-20.

May I know what is wrong? Or that shouldn't be the way I should be doing. Are there parameters I should change in the forceCoeffs block that are specific to the case that I am running? HELP!