Hull for Amphibius Aircraft - New Comer

Discussion in 'Boat Design' started by cjgadget, May 11, 2011.

  1. cjgadget
    Joined: May 2011
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    cjgadget New Member

    I am new to the group, and very poorly versed in hull design, or with anything pertaining to boats for that matter...

    I am a commercial pilot with a degree in aerospace engineering, with experience in control systems design(mostly electrical stuff). I am also building a composite aircraft called a Cozy Mk IV.

    I am doing some brainstorming on an aircraft design, similar to a Nardi Riviera. I have some idea of what the airframe design needs to look like and the construction methods used if I were to design with composites, but I am completely clueless about the hull. What types of constructions can be used? What is the work flow in determining the shape of the hull w/ regard to acceleration and speed requirements(takeoff distance). How due I assure the center of pressure and center of gravity locations provide for a stable hull? Are there simplifications I can make in the analysis.. i.e., can I just design a "boat" with similar weight/capacity to get a rough idea of things?

    I know this is an extremely broad inquiry. I do expect this endeavor to take up a good portion of my life(20-30 years). But, I am interested in starting learning - if not only to determine it'll always be outside my capability.. Any help or references would be very much appreciated!

    Thanks.

    -John
     
  2. Squidly-Diddly
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    Squidly-Diddly Senior Member

    how about skiis like the SeaDart?

    [​IMG]


    Note there was also a single ski(deep-V) version of this.

    I'd imagine the biggest fear of the seaplane pilot is finding you have nowhere to land due to sea-state.

    Skiis on mechanical shock absorbers should greatly increase the landable range of sea-state, and maybe the takeoff-able sea-state. Maybe incorporate land wheels into it.

    No idea about the 'work flow' in the calculations, but I've heard seaplanes reach takeoff speed but must be then 'snapped' off the water to break some suction.


    Another interesting amphib concept used a hovercraft style bag.


    Not this one....

    http://www.hovercraft.com/content/index.php?main_page=index&cPath=2

    It was a fully flying aircraft built in the late 1960s
     
  3. keysdisease
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    keysdisease Senior Member

    Republic Sea Bee

    Probably one of the most famous small flying boats of all time, the Republic Sea Bee

    http://en.wikipedia.org/wiki/Republic_RC-3_Seabee

    There is a perpetual story that "once upon a time" a Sea Bee forgot to put her gear down for a airstrip landing and landed on her hull. They jacked her up, dropped the gear and she taxied away none the worse.

    There is a pile of data on this aircraft, if you're not familiar with her she's a good place to start.

    Steve
     

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  4. Doug Lord
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    Doug Lord Flight Ready

    Excellent reference work: "The Design of the Airplane" by Darryl Stinton-all your questions are answered there as best I remember....

    Very cool new ultralight seaplane: http://www.flynano.com/

    click on image:
     

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  5. cthippo
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    cthippo Senior Member

    Welcome aboard, cjgadget

    Basically you need a planing hull with enough volume to support the weight of the aircraft. Most modern seaplanes also incorporate a stepped hull to assist in getting out of the water.

    You might also talk to Jeremy Harris on this forum. I know he builds aircraft as well, though I don't know if those include seaplanes.
     
  6. Squidly-Diddly
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    Squidly-Diddly Senior Member

    I see a slight prob w/Flynano's Prop-Ahead-of-Pilot's-Face arrangement.

    The prop blast would be around 100+mph of 'dirty air'.

    I've been on motorcycles with just goggles at 90mph and with full face helmet but no windscreen at 115mph and the wind-blast is distracting to say the least...and that is smooth "clean" air.

    I'd imagine you would have very nasty buffeting pulses from the prop at whatever the prop's rpms are, as well as major prop noise problem that wouldn't be solved with ear plugs.

    At least the Flynano has a very short range/duration.
     
  7. cthippo
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    cthippo Senior Member

    [​IMG]
     
  8. rwatson
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    rwatson Senior Member

    Couldn't see any actual real flying macnines, and there was no reference to them in the Aero 2011 that they said to look them up in.

    This has all the earmarks of 'vapour product'
     
  9. Doug Lord
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    Doug Lord Flight Ready

  10. viking north
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    viking north VINLAND

    CTHIPPO, CT, I have a spare cylinder (jug) from the engine in your french fighter if it is using the Gnome engine. :) photo below.
    KEYSDISEASE-friend of mine owned one of those in Stephenville NFLD. Like the bumblebee it's hard to imagine they could fly. It was painted a medium brown. He purchased it from somewhere Stateside, actually flown in and landed in Stephenville. I've been around aircraft all my life but this was the weirdest thing i've ever seen.
    CJGADGET- You're into some complicated engineering, boats married to aircraft, liquid, air, and fire to make it move--good luck
     

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  11. rwatson
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    rwatson Senior Member

  12. viking north
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    viking north VINLAND

    Wow--don't know if i'd be comfortable with a spinning prop right there in front of my face. I can just visualize a seagull strike. I bet you see this modified as a pusher in the Mark II version--
     
  13. claydog
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    claydog Junior Member

  14. Doug Lord
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    Doug Lord Flight Ready

    ==========
    They've got a prototype, they've done model testing-hardly a "vapour product"! I wish them luck-they're doing what every other plane manufacturer does. They're in the testing stage with a real airplane for crying out loud....
     

  15. Doug Lord
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    Doug Lord Flight Ready

    ======
    I like it-they say "hydroplaning tests complete". Seems they've sold 500 ahead... pretty good if it works as well as it looks.
     
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