Zero Coefficient of Lift Problem
 

Hi, I'm testing an airfoil at small angles of attack (alpha = 1,2,3,4,5) inside a antisymmetric tunnel, with the inlet 4D upstream from foil, outlet 8D downstream. I specify the proper reference variables and set up the force monitors to monitor lift and drag (with the proper force vectors), however in my results my lift coefficient is consistently equal to zero while I get non-zero results for the drag coefficient (I plot the calculated lift coefficient along the iterations and it stays zero).

I get a zero lift coefficient regardless of whether I run a steady analysis with inviscid, laminar, or turbulent models.

I do get non-zero lift coefficients when I did the analysis of the foil with farfield boundaries.

Do you know what the problem may be?

Thanks for any help you can offer.

MH