Bow wave cancelation

Discussion in 'Boat Design' started by Boston, May 17, 2009.

  1. Boston

    Boston Previous Member

    interesting input guys
    Ive been reading up on the whole thing lately and just now getting back to the thread
    my thinking was for a passive lifting body
    the bulb seems like it plows through the water
    the lifting body seems like it flies through the water
    the problem that I can see with the whole concept is that there are some articles about bow bulbs that suggest that some of the benefit is in maintaining good trim
    basically the tendency of the aft section to squat into its trailing wave is somewhat offset by the tendency of the bulb to want to dig in so to speak
    the idea I had originally was to try and get the lift to generate the trailing trough that would cancel the bow wave while at the same time lifting the bow slightly reducing wetted surface area
    something tells me it might still work if I had a softened exit and not a submerged transom area under wl or another wing were the trim plate might go to balance things out some
    getting to many appendages I know but hey
    its planning stages

  2. rasorinc
    Joined: Nov 2007
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    Location: OREGON

    rasorinc Senior Member

    Bos, go with a flared bow and a deep forefoot entry. Forget about a bulb.
  3. Ad Hoc
    Joined: Oct 2008
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    Location: Japan

    Ad Hoc Naval Architect


    You need to ascertain or think about your aim/objective..what is it you are trying to achieve..other than going around in circles looking at different ideas/theories. Until you dicide what it is you want to achieve, it is a constant circular argument. Everything is a compromise...
  4. Boston

    Boston Previous Member

    well then think of me like a vulture going round and round just waiting for the best Idea to drop dead

    I've had my head burried in home building for way to long and am just now getting back into all the things that made life a joy when I was a kid

    who knows were this will end up but I am itching to get back to the water

    was planning on the flaired bow and a keel depth entry anyway its just that semi displacement hull types eats power
    so I was hopeing to find a few tricks to improve efficiency on the basic displacement hull

    Ive got the main objective stamped on my forehead mate
    its written in here a few times in several places and Im hesitant to repeat it

    go to the diagonal planking thread I posted a while back if you want a clearer view of what Im up to

    the these alternator wind turbines are easy to make thread is were I got the idea and it kinda rolled from there

  5. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Boston, if your project is still along the lines previously discussed, then you'll gain nothing from this type of addition to your cruiser.

    I have recently done some experimentation with S/L 2.7 and less hull forms, in order to improve efficiency when at their upper speed limits. I've had good success on lean hull forms up to 33' (the largest I've tried so far), being able to reduce the HP requirement to speed and manage the wave train considerably. Drop me an email and I'll tell you about it.

  6. Boston

    Boston Previous Member

    it is
    wood, steam power, transmissionless, 60', 13 beam, 4.5 draft, low embodied energy,
    nothing set in stone but Ild love to get that 9 knots 12 max at 250 hp up to 12 knots 15+ max at 250 hp

    would love to hear what your ideas are
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