Comparative Numerical Study on Focusing Wave Interaction with FPSO-like Structure

摘要

Evaluating the interactions between offshore structures and extreme waves plays an essential role for securing the survivability of the structures. For this purpose, various numerical tools-for example, the fully nonlinear potential theory (FNPT), the Navier-Stokes (NS) models, and hybrid approaches combining different numerical models-have been developed and employed. However, there is still great uncertainty over the required level of model fidelity when being applied to a wide range of wave-structure interaction problems. This paper aims to shed some light on this issue with a specific focus on the overall error sourced from wave generation/absorbing techniques and resolving the viscous and turbulent effects, by comparing the performances of three different models, including the quasi-arbitrary Lagrangian Eulerian finite element method (QALE-FEM) based on the FNPT, an in-house two-phase NS model with large-eddy simulation and a hybrid model coupling the QALE-FEM with the OpenFOAM/InterDymFoam, in the cases with a fixed FPSO-like structure under extreme focusing waves. The relative errors of numerical models are defined against the experimental data, which are released after the numerical works have been completed (i.e., a blind test), in terms of the pressure and wave elevations. This paper provides a practical reference for not only choosing an appropriate model in practices but also on developing/optimizing numerical tools for more reliable and robust predications.