anyone tried hybrid of Hydrofoil & Wing-In-Ground?

IIRC there is a French(?) light amphib aircraft that has a pair of hydrofoil whiskers which seems like a good idea.

How about a combo of Hydrofoil and WIG were the foils would help the wing get up to speed in choppy water and the wing would help the foils raise the hull and floats off the water when foiling and the foils would become airfoils at higher speeds when fully flying.

 

Anything is possible, but no, I've never tried it, nor have I ever seen it done.
The foils would become a significant source of drag and induce sporadic, hard to control pitching.

 

I have designed and mocked up a model for just such a trimaran. Nowhere near as refined as a Doug boat but it may convey my idea better than a napkin. I'll take a photo and try to post it.

 

This is another take on the idea, probably not realized.
https://www.marstrom.com/sv/nyheter/marin/marstrom-stoder-v-rex-foiling-flying-sailing-farkost#

 

My apologies for the crudity of the model. But here is version beta .01.

 

When we tested our electric trimaran, we could see that we went slightly faster in headwind than with the wind. I can only explain it with WIG effect.
JS

 

HJS,

What are the specs on your boat?
Do you call it a stabilized monohull?

BB

 

You can call this creation whatever you want.
See more on:
10m LOA Electric Powered Trimaran for Flatwater https://www.boatdesign.net/threads/10m-loa-electric-powered-trimaran-for-flatwater.65884/#post-913344
JS

 

I proposed something like this a couple of years back. See the below screenshots of my shitty design and the thread..

https://i.imgur.com/a6V0XpT.png
https://i.imgur.com/TsHjaOJ.png
https://i.imgur.com/bq47y9B.png
https://i.imgur.com/q0KLke6.png

https://i.imgur.com/V5bZsg8.png

I believe we may be approaching foiling all wrong... https://www.boatdesign.net/threads/i-believe-we-may-be-approaching-foiling-all-wrong.63351/

 

Nice boat Iridian. I put my main hydrofoil forward of the Wig airfoil. My thought is the height stabilized hydrofoil will drag the wing behind it and as speed and lift increases the rear rises enough to eliminate the AOA and the added lift. I was hoping this will stabilize the craft fore aft during flight requiring fewest moving parts.

 

Just my old sketch from 1969.
JS

 

I'm referring to a combo of this (note hydrofoil whiskers that get in the water first rather than hull-slamp and belly flop into water and choppy waves).... A new generation of private plane: AKOYA, aircraft by LISA Airplanes http://lisa-airplanes.com/

And this (note it flies just over water and one of its main "issues" is when it encounters choppy waves it can't land any better than normal flying boat).https://www.wigetworks.com/airfish-8

The idea would be to use the hydrofoil whiskers to get it up on foil at fairly low speed in choppy waves to allow it to reach take off speed, and do same when landing. The big WIG wing should also greatly help the foils lift the hull before foiling speed (some WIG got props mounted in front of wing I assume to help create high pressure at lower speeds to lower take off speed). Once fully flying the hydrofoils would at least help at auxiliary WIG air-wings.

Just seems like WIG and whisker hydrofoils on a flying boat are a match made in heaven and could be mutually helpful.

 

There is a design called the Regent Seaglider that uses a planing hull, followed by hydrofoils, followed by full wing in ground effect flight.

I think a sail powered catamaran or trimaran could use hydrofoils plus a wing in ground effect crossbeam. So the aero lift means the hydro foils could be reduced significantly in size, which is probably what this thread is all about. It has to keep some kind of foil or hapa in the water for lateral resistance.

 

Trimaran Hydroptere comes close to what you want.
Just change the foils and make it more flying.
Keep in mind you need lateral resistsance to make sail propulsion possible, if the ship loses that it will blow away like a kite without a rope.

And be aware they had a lot of technical problems with hydropetere.

 

Also keep in mind that you need a way to control the lift that you add. The foils underwater are always controlled, either manually, with sensors, or by surface-piercing. If your added aerodynamic lift is a significant part of the total weight, you had better have a way to keep it from pulling the boat out of the water altogether or else you are headed for an unfortunate surprise.