In offshore environment, an accurate estimation of a wave-structure interaction has been an important issue for safe and cost effective design of fixed and floating offshore structures exposed to a harsh environment. In this study, a wave-structure interaction around circular columns in single and square array conditions was investigated with the regular waves. To simulate 3D two-phase flow, open source computational fluid dynamics libraries, called OpenFOAM, were used.
Wave generation and absorption in the wave tank were activated by the relaxation method, which implemented in a source term. To validate the numerical methods, generated Stokes 2nd order wave profiles were compared with the analytic solution with deep water condition. From the validation test, grid longitudinal and vertical sizes for wave length and amplitude were selected. The simulated wave run-up and wave loads on the circular columns were studied and compared with existing experimental data.