rash of new bubble-blower designs

Discussion in 'Boat Design' started by Squidly-Diddly, Nov 29, 2015.

  1. Squidly-Diddly
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    Squidly-Diddly Senior Member

  2. rasorinc
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    rasorinc Senior Member

    Very interesting concept. The hull shape presents no construction problems for wood, glass, or aluminum. Now, can you hang a 150 hp outboard on a 26' x 8' hull and use a 20 hp engine to power the fan and get good results. Lets hope some of the more knowledgeable members will chime in.
  3. upchurchmr
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    upchurchmr Senior Member

    I remember this idea from the 60's.
    But I don't think it was ever clarified as to why it didn't work. Or was not economical.

    Interesting that nothing was actually said about where the bubbles came from.
    Small dispersed holes might be susceptable to being plugged up.
    If you are riding on a carpet of bubbles, will you actually float, or will the boat sink until it is in contact with solid water?

    I am not quite sure why the bubbles reduce friction. Sounds like something for nothing.
  4. portacruise
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    portacruise Senior Member

  5. daiquiri
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    daiquiri Engineering and Design

    Regarding the question about the boat possibly sinking with bubbles beneath:
    The bubbles, in order to be stable (not collapsing or imploding), have to be at the same pressure as the surrounding water. Since they are at the same pressure, they will sustain the boat's weight just as the water would if the bubbles weren't there. So, no - the boat won't sink.

    The real problem is - how to keep the bubbles from escaping towards the water surface? I don't think that one has been resolved yet. Each single bubble requires a mechanical energy in order be pumped to the required pressure and expelled through the nozzle. That work is done by the air compressor, which requires power. So each bubble which escapes upwards into the atmosphere wastes that energy. If they all escape, that is a significant power loss.

  6. rasorinc
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    rasorinc Senior Member

    I pulled up Google and read a bit about air support hulls and the bottom shape controls Bubble loss which at speed rises above water line. There still is a large loss which is being re-supplied by the fan blowing new air in. The hull form creates an upward pocket for the air to collect.
    This compressed air lefts the whole boat above water line (DWL) so it is floating on a cousion of air.

    This makes the boat rise

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