Wash and Wave Resistance of Ships in Finite Water Depth

Abstract

This chapter develops a linear theory to predict wash and wave resistance of ships in finite water depth. The hull is assumed slender and the water depth is constant. The method uses the 3-D Green's function in finite water depth, which satisfies the classical linear free surface condition. Both sub- and supercritical speed are studied. The thin ship theory is used. The Green's function is studied carefully by different approaches. Wave resistance is predicted both by direct pressure distribution and by the far field wave systems. Vertical force and pitch moment are also examined. Steady forward ship motions in finite water depth are numerically investigated by thin ship theory and steady Green's function satisfying classical linear free surface condition in finite water depth. Both the wave part and the local disturbance of the Green's function are studied carefully. The methods are tested for a Wigley hull, and the results are compared with experiments and Tuck's shallow water slender body theory. Wash is discussed by systematically presenting results for the wave resistance.