[alirezab]

Hi everyone,
Sorry for another forceCoeffs question on this forum, but I have searched almost every thread and could not find what my problem is.
I am trying the extract the drag and lift coefficients acting on a cylinder submerged in a flow (in 3d). Cd is is calculated fine but Cl for some reason is too small compared to Cd. Almost 0. And I expect shedding for low velocities but Cl is almost constant. I have no idea why this is happening and would really appreciate any help.

Here is my force definition in controlDict:

        forces
        {
                type forces;
                functionObjectLibs ("libforces.so"); //Lib to load
                outputControl    timeStep;
                outputInterval 1;     
		rhoName rhoInf;   
                patches (obstacleLeft obstacleRight obstacleFront obstacleBack obstacleTop); 
                rhoInf 1000;                //Reference density for fluid
                nuInf 1e-6;                 //Reference kinetic viscosity for fluid
                CofR (0 -1 0);               //Origin for moment calculations
        }
        forceCoeffs
        {
                type forceCoeffs;
                functionObjectLibs ("libforces.so");
                outputControl   timeStep;
                outputInterval 1;
		rhoName rhoInf;
                patches (obstacleLeft obstacleRight obstacleFront obstacleBack obstacleTop); 
                rhoInf 1000;
                nuInf 1e-6;
                CofR (0 -1 0);
                liftDir (0 1 0);
                dragDir (-1 0 0);
                pitchAxis (0 1 0);
                magUInf 1;
                lRef 1;
                Aref 1;
        }

Thank you in advance,
A

[alirezab]

any advice would be much appreciated.
thanks

[Yuby]

Did you solve this problem? I have EXACTLY the same