rash of new bubble-blower designs

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

  1. Squidly-Diddly
    Joined: Sep 2007
    Posts: 1,677
    Likes: 106, Points: 63, Legacy Rep: 304
    Location: SF bay

    Squidly-Diddly Senior Member

  2. rasorinc
    Joined: Nov 2007
    Posts: 1,854
    Likes: 71, Points: 48, Legacy Rep: 896
    Location: OREGON

    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
    Joined: Feb 2011
    Posts: 3,054
    Likes: 150, Points: 63, Legacy Rep: 579
    Location: Ft. Worth, Tx, USA

    upchurchmr Senior Member

    History?
    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
    Joined: Jun 2009
    Posts: 1,120
    Likes: 32, Points: 48, Legacy Rep: 218
    Location: USA

    portacruise Senior Member

  5. daiquiri
    Joined: May 2004
    Posts: 5,373
    Likes: 247, Points: 73, Legacy Rep: 3380
    Location: Italy (Garda Lake) and Croatia (Istria)

    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
    Joined: Nov 2007
    Posts: 1,854
    Likes: 71, Points: 48, Legacy Rep: 896
    Location: OREGON

    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.
    https://www.google.com/search?q=air...FJ5xJf3vM:&usg=__5UhwQqd8oZpDdJFrodsb42Z5PZA=
    http://www.boatdesign.net/forums/bo...role-dish-large-air-supported-hull-40182.html



















    This makes the boat rise




















    g
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.