Drag Force ?

Discussion in 'Hydrodynamics and Aerodynamics' started by panther13, Apr 13, 2013.

  1. panther13
    Joined: Apr 2013
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    Location: Miami, Florida

    panther13 New Member

    What is the average drag force for a catamaran boat?:confused:
     
  2. jonr
    Joined: Sep 2008
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    jonr Senior Member

    42, but the units vary based on lots of things.
     
  3. FMS
    Joined: Jul 2011
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    Location: united states

    FMS Senior Member

    A 16' hobie cat or a 65' motor yacht catamaran? You need to provide a specific and detailed question to get any reasonable answer.
     
  4. panther13
    Joined: Apr 2013
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    Location: Miami, Florida

    panther13 New Member

    This is a school project. We were asked to design a shallow water solar / electric boat capable to carry from 10 to 15 people with 1' of draft. We are planning to use a catamaran 26’ long and 9.5 width with two sponsons ( 30 ‘’ wide each ) . We are planning to use to Torqueedo electric motors 48 V each. I was trying to run some simulations using solid work and it gives me 422 lbf of drag force. I have no experience working with boats, but I think that is a big number for a drag force value.what do u think ? Thank You for ur help?
     
  5. Leo Lazauskas
    Joined: Jan 2002
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    Leo Lazauskas Senior Member

    If you have the time, Michlet might give you some reasonable estimates for
    the total resistance.
    Be aware that the wave resistance can be very significant in shallow water
    when the depth-based Froude number is close to 1.0. That Froude number is

    Fh = U/sqrt(g*h)

    where
    U is speed (in m/s)
    g is gravitational acceleration (about 9.81 m/s/s)
    and h is water depth (in metres).

    Michlet is free and is available at:
    http://www.boatdesign.net/forums/design-software/michlet-9-30-released-46533.html

    There is also a paper on solar-powered multihulls that might help you at:
    http://www.cyberiad.net/library/multihulls/solar1/solar.htm

    Good luck with your project!
     
  6. quequen
    Joined: Jul 2009
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    Location: argentina

    quequen Senior Member

    This spreadsheet may help with the critical depth determination and Fh
     

    Attached Files:


  7. jehardiman
    Joined: Aug 2004
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    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    A cat may not be what you need given the design criteria. It will be difficult to get the required burden in a power efficient hull with only 1' draft. Cats are very load inefficient.
     
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