ON THE FLOW FIELD AND THE HYDRODYNAMIC FORCES OF AN OBLIQUING SHIP

This paper presents a method to calculate the flow field and the hydrodynamic forces of an obliquing ship under the free surface effect. The ship hull is treat as a thick wing of small aspect ratio. The ship hull is represented by the source distribution on the hull surface and the vortex distribution on the centre plane of the hull. The strength of these singularities are obtained from the boundary condition on the hull and the Kutta's condition. In order to obtain the wave flow, the Kyushu University method is used. This is a kind of Rankine source method and does not use the finite difference operator to satisfy the radiation condition. Since the flow field is calculated using these singularities, the wave pattern, the pressure distribution and the wavemaking lateral force and resistance acting on the hull are obtained. Using this method, the flow field around a Wigley hull with drift angle is calculated. The wave pattern and the hydrodynamic forces are compared with the experimental results. The agreements are satisfactory.