Fully-Nonlinear Simulation of the Hydrodynamics of a Floating Body in Surface Waves by a High-Order Boundary Element Method

The objective of this work is to understand and evaluate the hydrodynamics modeling of a floating rigid body in regular and irregular ocean surface waves. Direct time-domain numerical simulation, based on the potential-flow formulation with the use of a quadratic boundary element method, is employed to compute the response of the body under the action of surface waves including fully-nonlinear wave-body interaction effects associated with steep waves and large-amplitude body motions. The viscous effect due to flow separation and turbulence is included by empirical modeling. The simulation results of body motions are compared with laboratory experimental measurements. The nonlinear effects due to body motion and wave motion are quantified and compared to the viscous effect. Their relative importance in the prediction and modeling of a rigid body motion under various wave conditions is investigated. This study may provide essential information pertaining to develop effective modeling of nonlinear wave-body interactions which is needed in design of offshore structures and wave energy conversion devices.