How to find hydrodynamic lift from lift coefficient vessel? on planing

Discussion in 'Hydrodynamics and Aerodynamics' started by alfieb, Apr 18, 2011.

  1. alfieb
    Joined: Apr 2011
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    alfieb New Member

    Hi! I'm using savitsky's method to find the equilibrium trim angle for a vessel and was wondering how I can calculate the hydrodynamic lift generated? I already have the lift coefficient.

    Thanks for any help!
     
  2. DCockey
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    DCockey Senior Member

    How is the lift coefficient defined? What reference(s) are you using for Savitsky's method?
     
  3. alfieb
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    alfieb New Member

    Lift coefficient = Δ/((ro/2)*V^2*b^2). From Savitsky's '64 paper.
     
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  4. DCockey
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    DCockey Senior Member

    Re-arranging that formula results in:
    Δ = Lift coefficient*((ro/2)*V^2*b^2)
     
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  5. alfieb
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    alfieb New Member

    Ah ok, I thought Δ was equal to the weight of the vessel. But it is in fact the lift?
     
  6. DCockey
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    DCockey Senior Member

    Only if lift equals displacement. Is that consistent with Savitsky's assumptions?
     
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  7. daiquiri
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    daiquiri Engineering and Design

    Delta in the Savitsky formula is the vertical component of the hydrodynamic force (a force due to fluid dynamic pressure) acting on a prismatic hull moving through the surface of an inviscid fluid. It has to be added to the hydrostatic (buoyancy) component to obtain the total vertical lift.
     
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  8. rwatson
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    rwatson Senior Member

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