[JPMtz]

Hi everyone,

I have some problems with the calculation of coefficients (lift for now). I am using two methodologies that are not giving the same results :

For the fist one I take the forces values from forces.dat. I sum the pressure, viscous and porous forces along the same axis (in my case z) to get the total force. Then I divide this total force by 0,5*rho*S*U*U to get my coefficient.

For the second methodology I just use forceCoeffs providing the same values for rho, S and U of course.

The second methodology is the one that match best the exp. results. I made my research and found that the value given by the second methodology is rho times bigger than the value from the first : Cl_methodology2 = Cl_methology1*rho. I also know that OpenFOAM does not give the pressure directly but P/rho. My hypothesis is that the forces from forces.dat are also divided by rho. I tried to confirm this by looking into forces.c and forceCoeffs.c but I didn't understood well.

Could someone tell me if my hypothesis is ok or is anything else happening?

Thank you very much!!

Jean-Pierre