Simulation of ship motion response in head seas using a fully nonlinear potential flow method

This study develops a novel fully nonlinear potential flow approach for predicting the seakeeping performance of the KRISO Container Ship (KCS). We utilize a spectral coupled boundary element method for enhanced numerical efficiency and an acceleration potential-based technique for six degrees of freedom (6-DoF) motion calculation, together facilitating accurate simulations of ship-wave interactions. An overset mesh technique and an automated mesh-cutting process are introduced to accurately model instantaneous boundaries. Convergence analyses are conducted to validate the proposed method. Simulations of heave and pitch responses in head waves show good agreement with experimental and computational fluid dynamics results in literature, also demonstrating the nonlinear effects of large incident waves on ship motion. Moreover, the method accurately simulates parametric rolling and reveals the coupling effect between roll and other DoFs. •Spectral coupled BEM solves fully nonlinear potential flow problems efficiently.•Acceleration potential-based approach stabilizes ship’s six DoF motion simulation.•Robust techniques discretize free surface nodes and update boundaries accurately.•Heave and pitch in head waves are simulated with large wave impact analysis.•Parametric rolling and its coupling effects with other DoFs are investigated.