Is a 20% forced transition etc. in xfoil similar to adding a vg?
I understand a 20% forced transition in xfoil, is tripping the boundary layer from laminar to turbulent. Isn't that what a VG does?
A classic shaped naca foil like 2415, has a max cl of 1.5. I understand that vg's usually add a cl of about 0.5-0.7.
So... if I force a transition to turbulent at about 15-20% of chord in xfoil, shouldn't the max cl of a classic foil go up from 1.5 to about 2?
It doesn't....?!?