Investigations on gap resonance between two non-identical floaters with effects of floater heave motion

In this article, a two-dimensional viscous-flow wave flume is established using the open-source Computational Fluid Dynamics (CFD) software OpenFOAM to investigate gap resonance between two non-identical floaters. This study focuses on the combined effects of the breadth ratio between two side-by-side floaters and the heave motion of the upstream floater on the hydrodynamics of gap resonance. The upstream floater is assigned six different breadths, while the downstream floater remains a constant breadth. The wave height amplification in the gap, the heave displacement of upstream floater, the wave forces acting on floaters, and the response and the damping processes of fluid resonance in the gap are fully concerned. Results show that two resonance patterns emerge within the wave frequency range considered. The first pattern is characterized by in-phase movement of the water surface elevation and the upstream floater, while the second pattern exhibits no consistent pattern between the fluid and the floater. It is found that the first pattern exhibits faster response and decay processes than the second pattern. The resonance frequency of the first pattern is significantly affected by the breadth ratio, whereas that of the second pattern remains largely insensitive.