Dave, the fountain effect is the result of the slightly higher static pressure under the rotor forcing air past the rotor hub (now that Rotorheads have established that there is a measurable pressure increase). Since leakage causes lost lift for a given power requirement, it represents a loss in Figure of Merit. The best FM is always obtained for a uniform induced velocity. Above the fuselage this induced velocity clearly needs to be zero, but not negative.
The hub doughnut fairings, designed by CEFOSKEY, will reduce drag by reducing hub turbulence with the turning vanes forcing the flow to remain attached until the seperation point. It is like all things a compromise, but FM will go up.
I can understand how your mechanism would reduce drag, by aligning the "flying saucer" to the induced airflow. But this rotor system already has two swash plates, and i can't think of an aerodynamic way to make the fairings sit where they would need to be. The turning vanes are a simpler solution.
Bat1, great poster there.
