Calculation Of Wavemaking Resistance Of SAWTH Ships Using A NURBS-Based Higher Order Panel Method

One of the key techniques in SWATH design is the prediction and optimum design of the hydrodynamic performances (resistance and propulsion, seakeeping, maneuverability), whereas the resistance prediction is the most important task of hydrodynamic performance prediction. As with conventional ships, the methods of model experiment, theoretical analysis and numerical calculation are applied to predict the resistance of SWATH. Along with the development of computer scientific techniques and wide appliance in shipbuilding, numerical method based on CFD technique has become an effective tool for predicting the resistance and optimum design of ships.In order to predict the wave resistance of SWATH by applied CFD technique, this thesis presents a raised panel method based on NURBS for calculating flow, the wave pattern and wave resistance of a 3-D body advancing with forward speed on or beneath the free surface.In this thesis, NURBS is applied not only to represent the body geometry, disturbed free surface, but also to represent the unknown source strength distribution. This makes the geometry representation of the body shape and the wave pattern more precise. Rankine sources are distributed on panels of body surface and free surface. The source strengths are determined by satisfying the body surface boundary condition and the linearity free surface boundary condition, so that the velocity potential, the wave pattern and the wave resistance could be obtained. The radiation condition is satisfied numerically with collocation points shifting upstream.As applications of the method, flow around a 3-D body, the wave pattern and wave resistance of a ship are solved. The encouraging numerical results are achieved.This research is useful for hydrodynamic calculation of the ship by using CFD technique and for improving the techniques in prediction and optimumdesign of SWATH.