Problem with Slender Body mesh in Maxsurf

Discussion in 'Software' started by Zygan, Dec 30, 2017.

  1. drepaso
    Joined: Aug 2018
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    Location: LAS PALMAS

    drepaso New Member

    Hi guys! I am new here. Come because I have to design an autonomuos catamaran, in Maxsurf. I have read this thread and tried doing the same with other dimensions.

    To make sure I understood the process I changed the Zygan's model dimensions to my requeriments: 4 m length, 2 m beam and 0.6 m draft (0.8/0.9 m depth).

    But SB Mesh was very bad. I attached the image. What could be the problem? Maybe the short length?

    Thank you.
     

    Attached Files:

    • fail.png
      fail.png
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  2. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    Have you defined well the zero point and the baseline ?.
    Show us your Maxsurf file so we can analyze it.
     
  3. drepaso
    Joined: Aug 2018
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    Location: LAS PALMAS

    drepaso New Member

    Thank you TANSL
     

    Attached Files:

  4. drepaso
    Joined: Aug 2018
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    Location: LAS PALMAS

    drepaso New Member

    Ok, I fixed the problem. This was the demihull centreline offset in 'vessel type'. Thank you.
     
  5. sahbas
    Joined: Sep 2018
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    Location: Millan

    sahbas Junior Member

    upload_2018-9-10_12-38-41.png
    Hi guys, I am designing a 10 m catamaran. when I was trying a slender body in maxsurf resistance, I got this problem, could someone please help me to solve this
    thanks
     
  6. TANSL
    Joined: Sep 2011
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    Location: Spain

    TANSL Senior Member

  7. Kaarel
    Joined: Nov 2018
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    Location: Tallinn

    Kaarel New Member

    Hello! I'm trying to create a slender body mesh, but it isn't turning out the way I wanted. Can someone please explain why does this happen and how to fix this? meshproblem.PNG
     
  8. Camargo Aranha
    Joined: Feb 2019
    Posts: 3
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    Location: Brazil

    Camargo Aranha New Member

    Hello TANSL.
    I am dealing with Slender Body analisis of a Polinesian Canoe and I've tryed everything without success. it looks like the software only analises the main hull and do not consider the AMA asn you may see on the image. I will upload the Maxsurf file for your analisis, if possible. Kind Regards.
     

    Attached Files:

  9. TANSL
    Joined: Sep 2011
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    Location: Spain

    TANSL Senior Member

  10. Camargo Aranha
    Joined: Feb 2019
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    Location: Brazil

    Camargo Aranha New Member

    Hello again.
    thanks for your reply and it is strange that you cannot open it. Anyway, I am sending it again with a different name (just in case) and a picture showing the version of my MAXSRF which can now, be the cause of file not to open.
    Kind Regards.
     

    Attached Files:

  11. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    Try the following:
    - eliminate the surfaces that define the transverse beams. They do not add buoyancy and may complicate the model.
    - Remove one of the surfaces of the hullsdeck. You only need one to trim the surface of the hull.
    - place the baseline through the lowest point of the hull.
    - place the zero point on the base line, at the boat after end.
    - position the after and bow perpendiculars at the ends of the waterplane.
    - type of hull : catamaran
     
  12. Camargo Aranha
    Joined: Feb 2019
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    Location: Brazil

    Camargo Aranha New Member

    Hi again.
    thanks for your reply. I confess I didn't try your instructions because just before you answered me, I tryed something different and if worked, so I will post here also, so there will be 2 solutions for the same problem.

    1. Inside Maxsurf Modeler, I set all surfaces as asymmetrical
    2. Again in Maxsurf Modeler, I moved all surfaces sidewise to place the Main Hull in Port side and AMA on Starboard Side so the Demihull CL was at zero offset, with both hull's center lines at equal distance from Zero point.
    3. Vessel type set to Catamaran and Demihull CL was set to "zero"
    4. I kept my Zero Point at the bow and at DWL
    5. Inside Maxsurf Resistance's SB Analysis, I placed the Main hull offset to +0,75m and the AMA at -0,75m from Centerline and "VoilĂ " it Worked.

    Now I will try your advices and Certainly I will arrive at the same result.
    Thanks a lot.
     

    Attached Files:


  13. TANSL
    Joined: Sep 2011
    Posts: 5,498
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    Location: Spain

    TANSL Senior Member

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