Motions of a spherical submarine in waves

Abstract The free motions in waves of submerged vehicles with a spherical hull from but different metacentric heights are sought. The problem is analysed by considering the submerged vehicle as a neutrally buoyant sphere. The solutions to two independent problems, namely the radiation problem and the diffraction problem, are required. Nondimensional parameters known as the added mass, damping and diffraction coefficients for neutrally buoyant spheres are derived and computed values of these coefficients are presented in tabulated form. The responses of surge, heave and pitch are explicitly expressed by these coefficients and the metacentric height of the submarine. A spherical submarine is practically motionless relative to the particle movement of waves except at the vicinity of reasonant frequency, which is governed by the value of metacentric height.