[Steven] has been working for the past year on a very cool pedal powered hydrofoil, which he calls the Wingbike.
We’ve seen plenty of trampofoils before, which are hydrofoils that can convert a human bouncing up and down… to horizontal movement. There have even been some pedal powered versions before, but its a rather tricky mechanism to get just right.
[Steven] has built his Wingbike almost entirely out of carbon fiber, and it only weighs 10kg.The biggest problem is balance, as you’re about 1.5M above the foils. If you lean too much, you fall. If you slow down too much, you sink. The current model he is working on has fairly large foils, which does help a bit with the balance, but that also increases the amount of energy required to propel it. He plans on creating new designs with much smaller and faster foils in the future.
Unfortunately, the water is getting quite cold in the Netherlands, so he’s going to spend the rest of the winter months optimizing the bike from a design perspective. Stick around after the break to see his latest successful test video!
this thing desperately needs a power adder, specifically to confuse the shit out of everyone on the shore watching him ride this thing.
Recumbent Bicycle? lower center of gravity?
That and a little bit of flotation for when he stops would make this a viable vehicle.
like on a plane, seems that all commercial hydrofoil have dihedral to improve stability. Might want to change that flat wing.
That, according to my math (for planes when I did that) depends on the center of gravity ending up below (or closer to) the “center-of-lift”. It works for planes where they start out pretty close. But in this case you’re not going to win a lot.
Anyway, it DOES work when you make the wing stick out of the water if you start leaning. Then your lift drops on that side: It gives you stabiliity.
Some commercial full-sized hydrofoils them have a wing which always comes out of the water on both sides. This keeps them stable, as you describe.
What I don’t understand is how he intends to control roll, not just in terms of stability, but for turning. Maybe ‘ailerons’ on the rear wing?
Its not actually a change in the centre of lift that makes the difference with dihedral. When the plane rolls the lowered wing becomes more level, the other wing rises and increases it’s angle relative to the aparent gravity vector. The level wing has a larger effective wing area, increasing it’s lift. The effective wing area of the higher wing is smaller. Thus the lower/level wing generates more lift than the other and creates a righting torque that tries to roll the plane level.
What about a sweep back wing shape?
A friend of mine used to have one that you bounced up and down on to drive forwards. It suffered from the same basic problem – how do you get back on and restart when you’re in the water?
Wouldn’t it be possible to have some sort of inflatable buoy to resolve this? To remount, you inflate, climb on, and deflate while in motion? (A stretch to deflate I know)
http://hackaday.com/2012/04/25/hacking-the-trampofoil-to-be-pedal-powered/
It’s linked right in the article. :)
With a nice floater your bike would never sink, But then it would just be another surfboard-waterbike…
Very cool idea!
You could also do something like recumbent bike and canoe-like floatation. The lower center of gravity prevents tipping and the boat-like floatation prevents falling in every time you stop peddling.
Then use the wing structure in the water to raise the boat/bike while moving (reduces moving resistance and hopefully increases speed without sacrificing too much stability). Not sure if you could generate enough power to keep the boat/bike up for long, but at least you wouldn’t fall into the water every time you stop peddling.
See the wikipedia link for the general idea.
http://en.wikipedia.org/wiki/Sailing_hydrofoil
Spending childhood summers on cabins in Lake Michigan a family friend of ours had built a set of pontoon sided water bikes; one with a hydrofoil when (and if you had the power) you got the paddle wheel going fast enough it would lift nicely out of the water quite a bit! Pretty cool…they are nothing but piles of rust now as this was back in circa 1991-94.
edit: in/on**
There was an article in Scientific American in the late 80s/early 90s that involved the building of the pontoon hydrofoil – I think it may have been an episode of Nova as well.
I don’t know anything about the physics involved in that thing, and I don’t care. I do know this: If he perfects it, I will buy one.
Allan Abbott started this whole thing in the mid 80’s with the Flying Fish. I actually saw the Shutt brothers with home-made Hydropeds in the late 80’s. And MIT flew the Decavitator in ’92 to beat Abbot’s record with a mark that I believe still stands…
http://lancet.mit.edu/decavitator/images/flying_fish.gif
http://lancet.mit.edu/decavitator/images/hydroped.gif
http://lancet.mit.edu/decavitator/images/helmet.gif
I seem to recall Mark Drela being involved. His freely available software, xfoil and avl, is great for some cheap aero analysis (low speed 2d stuff in particular will kick the ass of any commercial CFD package you care to mention)
Wingbikium Floatiosa
http://www.srf.ch/player/tv/einstein/video/wasserfahrrad?id=d78162ed-3aaf-423f-bb77-e0b8f698b956 – (it’s in german). I don’t think it’s the same guy? 4:45
and it only weighs 10kg.
you joking right? metal would be even less than that