Exofish!....a WIG canoe

Discussion in 'Boat Design' started by Saqa, May 27, 2021.

  1. Robert Biegler
    Joined: Jun 2017
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    Robert Biegler Junior Member

    The engine is not the only source of noise. The propeller is noisy, too, though it is possible to make them less noisy (about 8 minutes in):

    I think I heard that pusher props are noisier because they operate in disturbed air flow, which is why those bent tip propeller tend to be popular with autogyros.

    Which reminds me of this:


    And this:
     
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  2. dreamingbarrierreef
    Joined: Oct 2018
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    dreamingbarrierreef dreamingbarreef

    That's what I call where paradise is. I'm surprised looking the vid the thing actually handles the kind of mild side wind fairly well there. If that's as much (wind) as it gets there, then you live in paradise man. But stronger side cross wind definitely could just flip over craft light as that. Or least it's gotta fly backwards. Downdraft also usually a big killer. But sea side no need to worry as much. Hope to see your finish build & vid soon.
     
  3. Saqa
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    Saqa Senior Member

    This is a good thinking exercise. I find the look and safety of a twin ducted prop system appealing. Been giving some thots to prop and motor combination that reasonably well in air or water. Could give some design flexibility to minimise some of the safety concerns of a light aircraft cross marine vessel
     
  4. Saqa
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    Saqa Senior Member

    Thats exactly what I was trying to draw Mr E's attention to a few posts back. He appears to have a very good handle on light craft handling issues so his comments on that craft behavior in those conditions would be very welcome but he seems to declined to review that

    Main problem area from his and others concerns is the light craft and wing area with wind gusts loss of control issues. I am thinking of a way to elliminate the wing then. I had an inspiration yesterday and been pondering it since

    I dont have access to anything like solidworks so would like to request someone to help me model a shape to figure out some volumes and such. Be great if the modeled shape can be scaled on the fly. Will be of great help thanks
     
  5. dreamingbarrierreef
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    dreamingbarrierreef dreamingbarreef

    Not sure if anyone has a private seat of the Solidworks. But I don't have. (Those guys that have lics are probably very hard to get their time..) Dejay has good suggestions in the other thread. I have feeling you'll have a lot of fun with this.
     
  6. Saqa
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    Saqa Senior Member

    Dreaming, I am having a lo of fun with this. I think I am on to something conceptually with where the design spiral is taking me, stand by for the craziest concept eveer :)
     
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  7. dreamingbarrierreef
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    dreamingbarrierreef dreamingbarreef

    hey man, I have to be honest with you, I thought your idea is real interesting and a good mind workout thing. But I thought it's gotta be crazy to do it for real, at first. I mean at first really.. But then there are loads of vids that showed it's been done by some real geniuses. Since you're really going for this, let me share some of my thoughts. Would be good thing if some of it could be useful.

    It was started with paraglider, and no it wouldn't work. It's gotta need a team to setup during launch, and it'll instantly become useless soon as it dips the water & get wet. Besides, it's slower than jetski. And these are all before how to make it fly 200km, with a heading, and the wind direction you can't control. So, true, paraglider seem unlikely.

    And somebody already proved hang-glider works! The wing can work so well. Looking at it turn into fairly good load of crosswind, the windward side just fills up & soaks up the momentary spike. And maybe plus the delta wing or swallow-tail / boomerang like wing design, the soft wing was stable & smooth. I'm sure somebody must already perfected that design. And it's not going to have problem handling any mild gust at paradise conditions. Which you already have there. So this can work in theory, but until you need to think about the range, 200km (& back?), with electric. I think it should work with petrol, but really don't know about electric. Not sure what type of ducted fan you might be able to get your hands on, but if it's one of those RC EDF, there are some like 4kW and gives about 6kg thrust. And you might need several of these to be able to take off. And 100Ah will only last for minutes at full power. 200km (x2 ?) gotta take quite a bit weight. And I doubt those motors are very rugged. Sea water is not only corrosive, it's very conductive. It could be immediate problem if any spray gets in.

    So if you're going with batteries, one idea might work could be an air-boat. Or probably should just call it an airship anyway. Maybe with a helium balloon to neutralize the takeoff weight, so you'll need less energy for the distance. But then, it still remains the tug of war man vs nature with the wind. Maybe you could reduce the buoyancy at altitude, and use some weight speed and altitude against a head wind; basically switch to glide mode. So you need a system to control the balloon volume too. And if you can make the balloon flatter, maybe even shape like a wing, a balloonwing!, it'll be more efficient moving forward, and could even take advantage of some updraft. But I think you'll need like hundreds of cubic meters of helium for just the couple hundred kg.. It's huge. And you'll need to have some superduper light weight frames. And it's probably preferable those ducted fans attached high, directly on the balloon.

    Anyway what you're doing is really very darn hard. I thought I'm nuts at times, but you win man. It'd be exciting to see your concept flying tho.
     
    Last edited: Jun 3, 2021
  8. gonzo
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    gonzo Senior Member

  9. Dejay
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    Dejay Senior Newbie

    No. But the IMO and International Civil Aviation Organization agree that a craft that is only capable of flight in ground effect or temporary "hops" should only be classified as a boat. I believe that should carry some weight if there are no laws to the contrary. This page links to most of the info I've found:
    Wing-in-Ground (WIG) craft https://www.imo.org/en/OurWork/Safety/Pages/WIG.aspx

    Also the Aron-7 was certified in 2020 as a "world first commercial wig craft" in Korea.

    From my limited research and understanding optimizing the ground effect (wider wing chord?) for fuel savings, but also having the craft stable if it hops outside of ground effect, and also being able to take off is tricky.
    For safety you'd basically want control surfaces like in a seaplane so that it theoretically can fly if it had enough power. But to take off you'd need a lot of power which could then lead to having to follow aircraft regulations. Maybe a single hydrofoil to reach take off speed.
    But depending on the regulations for ultralight aircraft you then might as well build an ultralight seaplane in the first place. Cheapest example being the powered hang glider with an inflatable.
     
  10. gonzo
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    gonzo Senior Member

    That's not correct. Both regulations apply, which means it also needs to comply with aircraft regulations. If you have any documentation or link that proves me wrong, I would be really interested.
     
  11. Dejay
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    Dejay Senior Newbie

    Sorry, all I've found is that this is the opinion of both organizations.

    Ok there is also this for Germany ("Craft that cannot exceed 30m above ground or water, e.g. hovercraft, are not considered aircraft" ยง 1 Abs. 2 Ziff. 11 LuftVG) and this.

    Of course laws could be different in each country but I would think that any news laws would "trend towards" the opinions of the international organizations.
     
  12. Saqa
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    Saqa Senior Member

    Gonzo
    I know you to be an experienced forumer. May I please ask the motivation for pulling out the silde rule on a wild "flight of fancy" (pun intended). May I also please request some expense of metal energies in condensing what really currently only is vaporware to something a bit more solid regardless how bouncy :)
     
  13. Saqa
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    Saqa Senior Member

    Dreaming, Dejay
    It's exciting to see some interest in this. I have pulled out the main points from your thots. I want to push each concept in discussion, even the failed ones, as the next person to notice the discussion might have an idea that will bring it back into contention again. Also Dreaming you are getting very HOT with your guess or should I say "gas" :D

    It's difficult to convey an idea without a pic. And I have too much on my plate to learn a CAD program right now. Let's try to find an image that looks like an upside down space shuttle. Also its funny reading the contention on regulations :)
     
  14. gonzo
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    gonzo Senior Member

    I question the statement that they are considered a boat by current law.
     

  15. Saqa
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    Saqa Senior Member

    I am sorry that you took exception to that, it's just a thinking exercise man... chill. Observation is that you have amazing energy pulling that up. Are you able to expand some of that into these ideas, or is that intention only that of pulling down the train of thought?
     
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