Research On Numerical Calculation Method Of Ship Squat In Shallow Water

This thesis deals with the squat of a moving ship,that is,the downward displacement and angle of trim caused by forward motion.In this thesis,the ship is considered into be moving in water of constant depth.Since squat is essentially a Bernoulli effect,viscosity is neglected throughout most of work which result in a boundary value problem involving Laplace's equation.For a ship moving in shallow water of constant depth,the water depth may also be small compared to the length of the ship.Inthis case,the flow becomes essentially two-dimensional,with horizontal flow velocities dominating over vertical flow velocities.All recent researches indicate that predication of squat depends on the following parameters:ship speed;ship position;ship geometry;channel geometry.The problem of ship squat is one among the crucial factor affecting the navigation of ships in restricted waters.The squat can be estimated using either empirical or analytical models.It may be implementing the real scale tests or Computation Fluid Dynamics technology as well.The starting point of any navigational or design analysis lies in the accurate determination of hydrodynamic force generated on the ship hull moving in confined waters.The analysis of such motion should include the effects of shallow water,ship squat,ship to ship interactions etc.It is natural to use Computational Fluid Dynamics methods for calculation of ship squat in shallow water.The comparison of the calculated result and measured result of real scale test shows that they are well agree with each other.And the Computational Fluid Dynamics methods can use for prediction of ship squat in shallow water.