NACA 4412 airfoil for Cd
 

The drag coefficient is negative at high angle of attacks!!

however at 0 angle of attack it seems to be OK.

the lift coefficient is acceptable and good at all AOA.

What is the problem.

I would say its my inputs when in the boundary conditions for pressure farfield;

i have it as X component= cos (10) and Y component = sin (10)

please help me