Thoughts on a size adjustable foil wing....

[thombiz]

We had family in for a visit two weeks ago and one of the toys the 4 year old brought to play with inspired some thoughts in me about foiling. The kid's toy was a metal jet fighter with wings that could be in numerous positions. It occurred to me that this concept could be used to make a front foil wing that could be adjusted to fit rider size. See the pics.

[dllee]

Wouldn't surface area be the same?

[isobars]

Yeah, but that MoFo would be faster'n hell.

[thombiz]

It occurred to me, instead of the wing tips swinging, they could just telescope. That would simplify adjustment.

[dllee]

There ya go, locking position, watersealed when extended, weight in control, stage adjustments, no insurmountable problems at all.

[grantmac017]

Last I checked the speed of sound in water is about 100× faster than any foil will reach. So a swept outline isn't going to gain anything.

If you want to have fun look up the 6 digit NACA profiles developed for low drag and stable center of lift. Specifically the ones used on the AC45 foiling cats. Then take a close look at the Slingshot Infinity wings.

[fathomfathom]

[grantmac017]

I can't seem to find the article, perhaps it was pulled?

Basically certain foil profiles have a fairly wide range of speeds before hitting a major drag wall and they can also offer a stable center of lift.
The early slingshot designs are very biased towards lift at the expense of drag and increased pitching moment. The later designs emphasize a stable center of lift and low drag. Because the drag is low they can use a larger wing which then increases lift at the bottom end.

If that makes any sense?

[dllee]

So WE are paying for the R&D so the companies reap the profits.
Pretty normal.

[fathomfathom]