Inclining Experiment

Discussion in 'Boat Design' started by mbhanoo, Apr 2, 2009.

  1. mbhanoo
    Joined: Apr 2009
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    mbhanoo Junior Member

    Hello Everybody,

    In the inclining experiment calculations, why free surface effect is added to the GM value. Since the value is too small, instead of neglecting it, why it is added to the GM. Please clarify.
     
  2. Ad Hoc
    Joined: Oct 2008
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    Ad Hoc Naval Architect

    You've written that slightly incorrect.

    GZ =GMsin(angle), so for small angles the shift of centre of gravity from the free surface is ineffect to "raise" the CoG. This rise in CoG creates the loss of GM, when you draw out the geometery of vectors.
     
  3. mbhanoo
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    mbhanoo Junior Member

    Yes sir, I fully agree with you. For small angles of heel, there will be negligible raise in KG hence no loss in GM. But I have seen in so many inclining reports, free surface correction GG0 is added to the GM value, even if it is too small. I request you to clarify that.
     
  4. Ad Hoc
    Joined: Oct 2008
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    Ad Hoc Naval Architect

    mbhanoo

    You misunderstand me. The formula and procedure IS for small angles and there IS an effective rise in CoG, for small angles, hence the reduction. So you're incorrect in assuming a "negligible raise in KG".

    For large angles the reduction is:

    (density -liquid/density-sea) x Inetria of tank/ Volume of ship

    see attached.
     

    Attached Files:

  5. Syam Krishnan
    Joined: Feb 2018
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    Location: Cochin

    Syam Krishnan New Member

    Hi,
    Please use XShip Inclining App available on the below link to make calculations easy. It will calculate all the parameters for you and give results and GM values and it's totally FREE...!!
    http://apps.xship.in/Inclining/

    XShip products - visit www.xship.in
     

  6. Syam Krishnan
    Joined: Feb 2018
    Posts: 4
    Likes: 0, Points: 1
    Location: Cochin

    Syam Krishnan New Member

    Hi,

    Please use XShip Inclining App available on the below link to make calculations easy. It will calculate all the parameters for you and give results and GM values and it's totally FREE...!!
    http://apps.xship.in/Inclining/

    Expecting your feedback also.
    XShip products - visit www.xship.in
     
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