Numerical investigation on the hydrodynamic wave forces on the three barges in proximity

Two-dimensional nonlinear hydrodynamic wave forces acting on three side-by-side barges are numerically investigated in this work. A finite volume viscous flow model, incorporating the volume of fluid method for freesurface capturing, is implemented based on OpenFOAM (R) platform to simulate interactions between nonlinear free-surface waves and multiple barges. The study explores the impact of fluid resonances in the gaps between three barges on the hydrodynamic wave forces. The initial transient and final quasi-steady wave forces are first examined to highlight the significance of transient evolution stage. The steady-state wave forces are subsequently concerned with the amplitude-frequency response of wave forces, along with the pressure and viscous force components. Relationship between wave forces and fluid oscillations within the gaps is then clarified to explain the mechanism of wave forces on the barges associated with gap resonance. Significant nonlinear higher-order harmonics are further demonstrated, with their origins closely linked to fluid oscillations within gaps between the barges. Contributions of higher-order harmonics to the overall wave force amplitudes are explored through harmonic analysis utilizing Fourier transformations. Finally, effects of the normalized incident wave amplitudes on the amplitudes of wave forces and higher-order harmonics are found to be highly dependent on frequency bands.