Maxsurf Resistance Method

Discussion in 'Software' started by Ruffner Sedurifa, Oct 1, 2024.

  1. Ruffner Sedurifa
    Joined: Mar 2022
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    Ruffner Sedurifa Junior Member

    Hi All . For an FRP V-shaped hull Fishing vessel (LOA= 27.75m, B= 5.24m) what method is suitable for resistance and power estimates? Is Holtrop ok to use?
     
  2. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    The attached table outlines the range of application of the method for various types of vessels.
     

    Attached Files:

  3. Van Callum
    Joined: Mar 2025
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    Van Callum Junior Member

    Hello all,
    I've some inconsistencies in the Maxsurf Resistance Module, someone could indicate me some possibilities to check and fix it?

    upload_2025-4-2_10-23-42.png upload_2025-4-2_10-24-11.png
     
  4. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    The figure on the left suggests that, among other things, the hull might not be correctly positioned relative to the coordinate system.
    Could you share your model?
     
  5. Van Callum
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    Van Callum Junior Member

    Yes
     

    Attached Files:

  6. TANSL
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    TANSL Senior Member

    I think you don't need more surfaces than the inner npl-hull and outer npl-hull. You can delete the others. If you want, you could also keep Surface Number 1, but Maxsurf doesn't need it for its calculations.
    Once that's done, define the surfaces as symmetrical and move them, for example, 0.7 m transversally.
    I think this will improve the calculations considerably.
    Snap3.jpg
     
    Last edited: Apr 2, 2025
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  7. jbasic
    Joined: May 2010
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    jbasic Josip Basic

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  8. Van Callum
    Joined: Mar 2025
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    Van Callum Junior Member

    Hello,
    I'm try to define a simplification hull directly on Modeler, defining different frames by Markers.
    However, I can't close properly the bow.
    Any suggestion?
    upload_2025-4-9_14-16-40.png
    upload_2025-4-9_14-17-13.png
     
  9. Van Callum
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    Van Callum Junior Member

  10. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    Yes, like most of us who use MaxSurf, you create a model in Rhino or AutoCAD (AutoCAD is better than Rhino) and export it to MaxSurf. MaxSurf's modeler is the most unfriendly I've ever seen.
     
  11. Van Callum
    Joined: Mar 2025
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    Van Callum Junior Member

    That was my first intention, but due to I get some problems when I defined the ref frame, I started to get the points which define the surface and reproduce the hull in the Modeler
    My problem is that the values at low speed makes me doubt.

    upload_2025-4-9_16-35-6.png
     
  12. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    You can't use Holtrop nor Savitsky for multihulls.
    Your hulls shapes in the first post seemed to be correct. Why did you change them?. Try to simplify them and use with the slender body method.
     

  13. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    Probably, if you create the model in AutoCAD, with the coordinate system correctly placed, you will not have any problems exporting it to Maxsurf in .igs format.
     
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