Negative Lift and Drag force problem
 

Hello Every one,

I am doing simulation of an airfoil for both coupled flow and segregated flow separately. But I am having problem with Lift and Drag force calculation. It shows negative values. Would you please suggest me why this is happening.

I have used Mach no: 0.2, angle of attack = 0 degree, k-e turbulence model.

Your cooperation is highly appreciated.

Thanks,
Rakibul

9/10 problems with aero cases like this are mesh related, check your mesh.