Comparison of nonlinear one- and two-way FFSI methods for the prediction of the symmetric response of a containership in waves

Abstract

This paper presents an investigation on the symmetric motions and loads of the S-175 containership undergoing severe green water impact that may result in high frequency whipping. Symmetric dynamic response results from two Flexible Fluid Structure Interaction approaches, namely one- and two-way coupling methods are assessed and compared in regular head waves. Numerical computations are performed by coupling CFD (Star-CCM+) and FEA (Abaqus). The creative meshing strategy adopted for RANS CFD simulations is presented and numerical predictions are compared against experimental measurements over a range of wave frequencies. It is concluded that heave, pitch and the linear wave frequency component in the wave loads are predicted well by the two approaches. However, overall two-way coupling compares better with measurements and a significant difference between the two different methods is especially noted in the high-frequency whipping domain. It is concluded that one-way coupling underestimates the high-frequency vibratory components and therefore care must be enforced when applying this method for calculating hydroelastic responses in waves.