Seeking Ground Effect Craft Info

The smallest most efficient design that flew is probably the Hoverwing 2VT by Fischer. WIG make more sense the larger they are. It is at least a matter of avg wave height vs still efficient flying height.

The hovercraft UH-10 with simple WIGs attached is probably the smallest just for fun hybrid ground effect craft.

A very knowledeable aeronautical engineer designed the smallest manned WIG craft possible a while ago with skin on frame battened Lippish wings and high tail and small motor for airprop. Kickstarter did not exist then. It might not have made a difference.

I seriously doubt that a WIG glider pulled by a motorboat, unless perfectly glass water surface, could be made stable in pitch at that small scale. Could use a small and slower version of an aircraft carrier's catapult. Or could ski downhill and glide on the wings and ... fall softly in the snow.

 

portacruise,

Very interesting question! I believe that without a rider on board the wing will be inherently unstable and will probably "somersault" backwards and flutter down to the water, much like a surfboard does when you fall and the wind catches it.

The wings might also catch the water and stop suddenly. If the rider is on board when this happens they would be pitched over the front, but that's not too dangerous due to the very low speeds involved. This happens all the time wake boarding especially when landing a big jump.

With the rider on board, I believe the wing will be able to coast to a stop on the surface when the rider lets go of the handle.

 

lucdekeyser,

Thanks so much for the feedback and interesting ideas. One thing to keep in mind about all those smallest WIG craft is that they are also carrying the weight of engines, fuel, and mechanical flight control surfaces. I propose that by eliminating that weight it can be done even smaller. Also, efficiency is not too much of a concern either. A very high drag design is actually desirable in this case.

The pitch stability is my biggest concern. One contingency plan I have is to add two small horizontal stabilizers if the prototype is excessively unstable, but based on personal experience, I'm not sure if they will be necessary.

The downhill idea sounds awesome and terrifying! How would you slow down or stop? I love the outside the box thinking! I had never considered using it on snow.

 

Have you looked at the manta ray inflateable towable . It flies off the water with 2 riders at fairly slow speeds but I think they have been banned in places because of several bad accidents.

 

all of them, at any time, in a millsecond.

WP's mention of the manta ray is a good reference. Check out the stability of this thing with about 6 feet + of trailing control surface.

Its damn wobbly even then,




edit.

oh, and i found a wobbly one in action

 

Corylunn, WIG craft make only sense if you most positively must stay out of the water for cruising. Otherwise, you might as well use the water medium, up to a certain speed, because it is so much easier to design control surfaces for. As one of the contributors remarked in similar vein, air is just transparant smoke. And it reacts in surprisingly strange ways when pressed against a surface by a foil. Even without any waves.
But I know you will not be detracted. Just promise to put all video's of the testing on line. They may be worth a kickstarter on their own ;-) And wear a helmet.

 

rwatson,

The wake wing was designed specifically to address the dangers of those ridiculous flying inflatable towables, and I wish you wouldn't compare my design to them. First, the tow rope is not attached to the wing, unlike the manta ray. Second, the wake wing travels at MUCH slower speeds to fly than the manta ray. Third, If the boat goes too fast, the drag will be so high that the rider will have to let go. That way it will never fly up high and "kite" out of control like the manta ray. Fourth, the wake wing is a flying wing that gets a boost from ground effect. It does not rely on it, but it makes it very difficult to fly as high as the manta ray. Fifth, the manta ray is barely designed to fly. The wake wing has tails and a real foil shape.

If anything, the fact that the inefficient and dangerous design of the manta ray flies at all leads me to think the wake wing might be successful.

I can see how it is easy to compare the two concepts and to easily be afraid of the wake wing but the differences really are important. That is what sets it apart.

 

lucdekeyser,

I will certainly post pictures and videos as soon as it is built and out on the water being tested! Also, it may not be the most efficient form of transport, and it might require decent weather conditions, and it might take a lot of testing and changes to get right, and it might be difficult to learn to use, but all that would be worth it because it would FUN! Skimming above the waves on a wing that I'm standing on is a dream that I want to make a reality, and I still think it is very possible. No one has even tried this before (maybe because it's impossible). Without trying, we will never know. I think it can work, and I'm willing to try because the fun would be worth it.

 

Without being insulting, in the spirit of discussion, Your concept is only in your mind.

The manta actually works, albeit in a primitive way. However, you will encounter all the same problems it has, plus the problem of operator controlled trim.

I wont add any more comments to this thread, as I don't want to bore everyone with repetition.

I will keep an eye out on your progress though, and wish you luck on your learning journey. Stay safe

 

I don't think the manta is too far from your idea at all. Still basically the same principle. I hope you are successful. I like people to push the boundaries. 1 thing I wonder is how much strength will it take to hold on to the tow rope once you get airborn .

 

At least 2/3 rd less than in the water. Until back in the water.

 

First of all good luck to you on making this work. First off, I would not invest a lot of time and money at first. This may sound crude but build a small, cheap proof of concept first and see if you can make something work. No need for complicated math or much money at this stage. A block of polystyrene carved into whatever shape foil you desire. Carve your winglets, and attach with packing tape. Attach a tow line to the underside where ever you desire. Tow vehicle-a bicycle. If you manage to get that to work, scale up from there. Again there is no need to waste a lot of time and money into your project until you get a proof of concept to work first. The further you get into this project the more problems you will find.
Good Luck
Dan

 

Sailor Dan,

Thanks for the advice. I really wish I could justify building a towable model but the wing is designed to be inherently unstable. It will only achieve controlled flight with a rider on board making fast and constant adjustments. If I were to try and tow a model of it behind a bicycle it would almost certainly flop about and spin in circles. Without the rider, there is no chance of it working. Also, attaching the towline to the wing would create a whole new angle of pull on the wing, changing much of it's behavior. If any of the naysayers out there saw a video of a model unable to fly straight and level everyone would immediately point and say, "See! It will never work!". Lots people said the same thing when I was designing and building my first foilboard, which ended up working great! Still, I take your advice seriously and intend to build the prototype as inexpensively as possible so that I have funds left to do extensive modifications as necessary to achieve controlled flight above the water. In the end building and testing and modifying a full size prototype really is the next step to take.

If I get deep into this project and there really isn't any way that it will work, at least I will have tried and added a little bit to the world's knowledge of such things!

I really appreciate the good luck wishes!

 

John Connor

John Connor built a successful towed WIG during his GT-200 project. It was a model of a larger craft, but nevertheless it was a fully functional WIG that flew stably at 20-30 knots when towed on the canals of Fort Lauderdale.

I think your concept is feasible....although I'd like to see the numbers.

 

cmckesson,

I am really interested in finding out more information about the GT-200 project. I did a google search and searched this forum and couldn't find anything. Do you have any links, pictures, or any more information about it? It sounds really interesting.