Wingtip vortices in a wingsuit.

[inviscid-lift]

If you are not familiar with what a wingsuit is- you should google it.
Now...
Let's assume we have ourselves a wingsuit flyer in flight (or rather glide). Let's assume the arm-wings produce vortices on the wingtips and that these vortices hit the wingtips of the leg-wing ( which are where the feet are ).
Does that increase or reduce drag on the leg-wing?
What do you think is the effect of the arm-wing downwash on the leg wing?
(glide ratios for wingsuits are about 3:1 nowadays)


Cheers

 

[Dr Lots-o'watts]

I doubt wingtip vortices from such a small falling weight as a human are a significant drag force, compared to the overall drag of the "aircraft". In addition, the arms are usually spread wider than the feet. Finally, it seems to me that for a glide ratio of 3:1, the legs would constantly remain below the vortices' path.

 

[inviscid-lift]

As for the vortice-path and glide ratio- the vortice may hit the feet. The angle of attack varies, and the hands may be positioned in such a way that the vortice lines go 'through' the feet (leg-wing wingtips).
IF they do, even if thay are small, do they increase drag on the legs or do they decrease it?

 

[Dr Lots-o'watts]

I can't see how it can help, and my best argument is that I can't think of any aircraft that has any parts of itself flying into its own vortices. In general, they harm laminar flow. I think you would need a very special and particular geometry for vortices to be somehow helpful to flight, and I'm not aware of any such geometry at the moment.

 

[inviscid-lift]

Let me then put it this way. The leg-wing of the wingsuit (and let's concentrate on the wingtips / feet) gliding through :
1) still air
2) "vortice-affected" air
What will be the difference in aerodynamic DRAG that the leg-wing experiences in 1) and 2) ?