WAVE RADIATION AND DIFFRACTION BY A SUBMERGED SPHERE IN A CHANNEL

Wave radiation and diffraction by a submerged sphere is analysed based on the linearized velocity potential theory. The solution is obtained based on the multipole expansion which satisfies the boundary conditi ons on the free surface, at infinity and on side walls. The coefficien ts in the expansion are obtained by imposing the body surface boundary condition. Results are obtained for the added mass, the damping coeff icient, the exciting force and the drift force. Some of the results ha ve been compared with those obtained from alternative equations and th ey are all in excellent agreement. The effect of the trapped mode is a lso discussed. It is found that this effect becomes evident when the s phere is close to the free surface and the channel is very narrow.