Wave–current-structure blockage: Development of one-way hydro-structural coupling for a jack-up platform in waves and current

This paper introduces a novel application of porous block approach to derive hydrodynamic forces on a generic jack-up platform in waves and current using OpenFOAM. The objective is to account for fluid force reduction due to wave–current blockage effect. In parallel, following Santo et al. (2018), a one-way coupling is developed and presented to map the resolved hydrodynamic forces from OpenFOAM to structural beam elements forming the legs of the jack-up platform in ABAQUS (so called OF-ABAQUS coupling solver) to derive dynamic response of the platform when it is at elevated condition (or in-place). Sensitivity checks are performed to ensure the developed OF-ABAQUS coupling solver is robust. The development is compared with ABAQUS simulations, which make use of the standard Morison equation with relative velocity formulation to derive the applied hydrodynamic forces. Waves with in-line current are considered. At the structural resonance, we observe reduction in the amplitude of the dynamic response, which is attributed to the wave–current-structure blockage effect manifested as additional fluid damping not present in the standard Morison and present industry recipes.