Hydrodynamic coefficients for groups of interacting vertical axisymmetric bodies

Abstract

The paper deals with the linearized hydrodynamic forces acting on multiple vertical axisymmetric bodies forced to oscillate either independently or as a unit in water of finite depth. For the solution of the radiation problem an exact semi-analytical method is developed which combines the single body hydrodynamic characteristics with the physical idea of the multiple scattering approach in order to account for interaction phenomena. By superimposing various orders of radiated/scattered waves emanating from one body oscillating in the vicinity of the others, the velocity potential around each body of the multi-component system is obtained. The present method is applicable to arrays consisting of an arbitrary number of vertical axisymmetric bodies having any geometrical arrangement and individual geometry, provided that their vertical projections do not intersect. Extensive numerical results are presented concerning both the hydrodynamic coefficients of various multi-component structures and the corresponding interaction coefficients among their individual members for configurations commonly used in offshore applications.