Harmonic structure of the nonlinear force on a fixed ship-shaped floating production, storage and offloading vessel under dispersive phase-focused wave groups

This paper presents a numerical investigation on the harmonic structure of hydrodynamic forces fixed and simplified representative floating production, storage offloading (FPSO) vessel hull under dispersive phase-focused wave groups. The high-fidelity model utilizes two-phase flow solver in open-source toolbox OpenFOAM. A series cases were computed using model, where effects steepness, bow diameter, length FPSO are investigated. It is found that given an different non-dimensional inline force exhibits remarkable similarity terms temporal development. only weakly dependent steepness incident group but strongly length. When k p L = 2.27, kp number at peak frequency, diffracted significantly by FPSO. entire wave–structure interaction process largely linear, transfer between harmonics rarely seen. However, when kpL further reduced to 0.57, globally disturbance far field reduced, locally nonlinear occurs rear FPSO, severe run-up downstream stagnation point. Higher-order excited, becomes much more nonlinear.