Stability Analysis - Trim problem

Discussion in 'Stability' started by Diego San, Jan 21, 2015.

  1. DCockey
    Joined: Oct 2009
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    Location: Midcoast Maine

    DCockey Senior Member

    For static equilibrium the vessel sinks/rises and trims until:
    - the displacement equals the weight of the vessel
    - the vessel trims (and heels if CoG is not on centerplane and/or vessel is not transversely symmetric) until the Center of Gravity is over/under the Center of Buoyancy.

    Note that as the vessel sinks/rises the CoB position may change for a given trim angle. If the analysis is done for different weight and displacement than the design condition, then the equilibrium trim may be different than for the same CoG position at a different displacement. The Center of Floatation position will indicate which way the CoB will move for a small increase in displacement. If CoF is aft of CoB then the CoB will move aft for a small increase in displacement. If CoF is forward of CoB then the CoB will move forward for a small increase in displacement. CoF is determined by the shape of the waterplane.

    Diego San, did you design so that the CoB is aligned with the estimated CoG at the design condition, and your initial question was about trim at a different displacement?
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