Variational Principles Associated with Motions of a Floating Body in Waves and Their Mutual Relations : A Reasonable Introduction of the Radiation Condition

Abstract

Ships and offshore structures make complicated motions in waves. The estimation of their motion is very important to assure their safety. Many methods have, therefore, been developed to discuss the motions of a floating body. In this paper, methods based on variational principles are discussed. A irrotational flow such as water waves of an incompressible and invicid fluid can be dealt with in a unified manner using variational formulations derived from the Hamilton principle. In this paper, the mutual relations of these variational principles are discussed in detail. And the radiation condition of diverging waves is also introduced in a reasonable manner.