Study on Wave Loads during Steady-State Gap Resonance with Free Heave Motion of Floating Structure

Fluid resonance may occur in a narrow gap between two side-by-side vessels under wave actions, which can cause significant wave height amplification inside the gap and further induce large wave loads and motion responses of the vessel. Based on an open-sourced computational fluid dynamics (CFD) package, OpenFOAM, the steady-state gap resonance phenomenon formed in between two side-by-side boxes and triggered by the incident regular waves is simulated, where the upriver box keeps fixed and the downriver one heaves freely under wave actions. This article comprehensively investigates the influence of the vertical degree of freedom of the downriver box on the wave loads exerting on both boxes and further reveals how the relative position of the heaving box with respect to the incident wave direction affects the characteristics of wave loads during the steady-state gap resonance. The results show that both the normalized largest wave loads and the dimensionless wavenumber where the normalized largest wave loads occur are significantly affected by both the incident wave heights and the relative position of the heaving box to the incident wave direction.

Automated summary

Fluid resonance can occur between two side-by-side vessels, leading to amplification of wave height and increased wave loads and motion responses of the vessels. This study uses the OpenFOAM software to simulate the steady-state resonance phenomenon between two side-by-side boxes under incident regular waves, with the upriver box fixed and the downriver box heaving freely. The study investigates the influence of the vertical degree of freedom of the downriver box and the relative position of the heaving box on the wave loads exerted on both boxes during the steady-state gap resonance.