Wave interaction with a bottom-mounted body in front of a vertical wall using an exact DtN boundary condition

Abstract

Recently, Rim1,2 suggested an exact DtN boundary condition to study the three-dimensional wave diffraction by a floating body or undulated seabed for horizontally-unlimited water domain of finite-depth. This paper focuses on linear wave interaction with a bottom-mounted body in front of a vertical wall. An artificial boundary is chosen as a virtual cylindrical surface so that it can enclose two bodies (one is the original body and another is its imaginary body by the method of mirror image), and the entire water domain is divided into an interior subdomain and an exterior one by the artificial boundary. An exact DtN artificial boundary condition on the artificial boundary is derived from an analytical solution in the exterior subdomain, and it is used as a boundary condition to solve hydrodynamic interaction of the bodies with the interior subdomain numerically using boundary integral equation. The present numerical model is validated by comparison with ANSYS AQWA in case of a bottom-mounted circular cylinder. The effects of heading angle and distance from the wall to the body on exciting forces are considered.