getting wrong forces and force coefficients in openfoam
 

hello everyone,
I'm running a 2D compressible naca0012 airfoil simulation at velocity 165m/s using rhoSimpleFoam solver.
The simulation ran fine and i got accurate pressure and velocity contours as well as able to plot Cp vs x/c using paraview.
But the values of the coefficients are way off than the standard results.
Cl values are coming in the range of e-24 and same goes for the forces.
To calculate forces and force coefficients i used the following code in the controlDict:
function
(
forces
{
type forces; // use the forces class
functionObjectLibs ("libforces.so"); // "plugin" library to load
patches (aerofoil_wall); // Name of patches to integrate forces
//outputControl outputTime; // When to write the output
rhoName rhoInf; // Name of the reference density
rhoInf 0.000518; // Reference density for fluid
CofR (0.33333 0 0); // Origin for moment calculations
outputControl timeStep;
outputInterval 1;
}
forceCoeffs_object
{
type forceCoeffs; // compute force-coefficients
functionObjectLibs ("libforces.so");
patches (aerofoil_wall);
//outputControl outputTime;
rhoName rhoInf;
rhoInf 0.000518;
log true;
CofR (0.33333 0 0);
liftDir (0 1 0); // lift direction (parallel to U_inf)
dragDir (1 0 0); // drag direction (normal to U_inf)
pitchAxis (0 0 1); // rotational moment axis
magUInf 165; // magnitude of U_inf (for normalization)
lRef 1.0; // reference length
Aref 1.0; // reference area
outputControl timeStep;
outputInterval 1;
}
);
I have attached the force and force coefficient.
Attachment 67868

Attachment 67869

Can someone please tell me the reason for error or what am i doing wrong.

Thank you

What fluid are you using to have such a low (5e-5) density value? air is around 1.2, which is what I assume you are simulating.

now when i tried this same setup in another system having openfoam and calculated the forces i got correct values.
so it means that there is no problem in the above code or setup but something the way openfoam is calculating in the previous system.
I am no expert so someone help me why is it happening