Tuesday, August 16, 2011

Tip vortex reduction by tip propeller

We were discussing with Kate about possibilities to use tip propellers, in tractor configuration. Tractor configuration would cause a swirling motion to the opposite direction of the tip vortex before the tip wortex forms and it would reduce the tip vortex. Therefore the propeller at the wing tip would give more efficient dynamic thrust for the plane than propeller at some other location in the aircraft. In cruise condition when the tip vortex is low with low span loading wing, this could eliminate significantly the unfavorable tip vortex. With electric motors, additional tip propellers would be fairly easy to arrange.

Some analysis would be needed how much this would help. Of course it would depend on the weight of the plane. The heavier the plane, the more leakage to the tip, the more tip vortex would form. The bigger the benefit of having a opposite direction swirling motion to nullify the tip vortex formation.

1 comment:

LR said...

Any good references on this, or proposed designs?
Was just digging up info re Guy Stevenson's Econo Cruiser 3000, which uses this concept, but can't find much. Wonder if it's just a "paper" airplane?

Of course there's always the Vought V-173. And I've seen a paper someplace on a business turboprop with some kind of prop mounted on the rear of the wing tips. Not sure if driving or harvesting power from the vortex.