Author(s)

S. H. Mousavizadegan, I. Ghamari, R. Abid & M. Rahman

Abstract

Marine structures are usually designed to operate in a wave environment. Structural loading of the body surface under the water and unsteady motions of the body are two of the principal resulting problems. A body in waves is also acted upon by steady forces and moments due to the reflection of the wave energy and as a consequence, the body starts drifting, depending on the rigidity of the constraint. The drift loads on marine structures are important in designing mooring or dynamic positioning devices. The most general way to compute these steady loads is the application of the pressure integration around the wetted surface of the body. An exact solution for the computation of second-order drift forces and moments for arbitrary bodies are presented using a non-singular boundary integral equation method (NBIEM) and the application of B-spline to model the wetted body surface in wave. The influences of radiation velocity potentials on drift loads are investigated for different types of bodies. Keywords: drift forces, wave radiation, second-order steady force, wave-body interactions, arbitrary bodies, spherical structures, boundary integral methods. 1 Introduction Marine structures are usually designed to operate in a wave environment. Structural loading of the body surface under the water and unsteady motions of the body are two of the principal resulting problems. When the characteristic body dimension is comparable to the wave length, the potential effects dominate. The presence of the body alters the pattern of wave propagation in the vicinity of the structure and causes wave scattering. The body may also oscillate and cause the radiation of waves if the constraints are not sufficiently rigid. As a consequence,

Keywords

drift forces, wave radiation, second-order steady force, wave-body interactions, arbitrary bodies, spherical structures, boundary integral methods.