Johng,

Fine, you can build a 2D wing in a wind tunnel. You can't build a plane with one.

You can't reduce the tip vortex strength without reducing lift. You can modify the effect of the vortex's downwash on the wing, consequently affecting induced drag. Believe it or not.

A wing must exert a net force down on the air to provide lift to the plane. This, not a local pressure difference at the tip of the wing, is the cause of tip vortices. The only way that air, as a fluid, can provide the reaction force to the wing's downward push is to flow. Part of the resulting flow is the tip vortices, and their overall strength depends on the amount of force (lift). How the 'downwash' part of the vortices affects the wing depends on other factors ( aspect ratio, spanwise lift distribution, tip treatment, etc. ), in addition to the amount of force. Those other factors are the reason that induced drag can be reduced somewhat without reducing lift.

banktoturn