Calculation of ship squat in restricted waterways by using a 3D panel method

A panel method is applied to calculate the sinkage and trim of a ship sailing in a shallow channel. The hull surface, free surface and channel wall surfaces are discretized into panels on which Rankine sources of constant strengths are distributed. An iterative scheme is used to deal with the nonlinear boundary conditions on free surface. The boundary condition on water bottom is satisfied by the method of images, whereas the radiation condition is satisfied by raised panels above free surface. The vertical force and pitching moment are obtained by integrating the hydrodynamic pressure over the hull surface, and the sinkage and trim are calculated according to dynamic equilibrium. Numerical calculations are performed for Series 60 (CB=0.6) ship. The numerical results are in good agreement with experimental data.