Numerical Simulation of Fully-Nonlinear Wave Motions around Arctic and Offshore Structures

The present paper describes the numerical estimation of maximum wave run-up and higher-harmonic forces on an Arctic and offshore structures using a Numerical Wave Tank (NWT) simulation technique. A finite-difference method and a modified marker-and-cell (MAC) algorithm are adopted to calculate wave forces and wave run-up on an Arctic and offshore structures of arbitrary shape, and to investigate the characteristics of nonlinear wave motions and their complexity of interactions with structures The Navier-Stokes (NS) and continuity equation are governed in the computational domain and the boundary values updated at each time step by a finite-difference time-marching scheme in the frame of rectangular coordinate system. The fully-nonlinear kinematic free-surface condition is satisfied by the marker-density function technique The results by NS-MAC NWT simulation for an Arctic structure are compared to the predictions of linear diffraction analysis, based on an integral equation method for vertical axisymmetric structures. For an offshore structure the simulated results are also compared with those of other numerical methods and measured data.