Wing tip vortices are evident from airliner vapor trails, and helicopter
blade slap. Elliptically loaded high aspect ratio tapered wings have
minimum induced drag but cannot eliminate it. Different methods are
disclosed herein, for upper and lower surface boundary layers to cancel
their opposing vorticity upon shedding from the trailing edge, thereby
eliminating wake vorticty, induced drag and associated noise. This
requires wing-rotor-propeller or fan blades with a platform designed for
uniform bound circulation and with boundary layer control near the tip.
In addition this requires special techniques to counter span-wise
pressure gradients, such as tip circulation control blowing or an upwind
small propeller or wind turbine on each tip. These techniques can
eliminate wake vorticity with its induced drag, noise, flying on the
backside of the power curve and the option for asymmetric loading by
pneumatic means to eliminate need for cyclic pitch control or
conventional ailerons.