Numerical Study on Hydrodynamic Interaction Between Two Parallel Ships Advancing in Waves Taking Surge Into Consideration

Abstract This study investigates the hydrodynamic interaction between two ships in waves through both model tests and numerical methods, utilizing KCS and DTMB5512 ship models. A functional-decomposition hybrid solver of potential and viscous flows, HUST-SWENSE, is developed to predict four degrees of freedom (4DOF) motions and forces for single-ship seakeeping as well as hydrodynamic interaction between two ships travelling in parallel under wave conditions. This solver is based on the Spectral Wave Explicit Navier-Stokes Equations (SWENSE) model, which decomposes the total physical field into incident and complementary components. The incident wave field is generated and propagated using potential flow methods, while the interaction between waves and ships is modelled through a viscous flow approach based on SWENSE equations, enhancing computational efficiency by reducing grid requirements for wave propagation. A comparison of simulation results with experimental data reveals that the simulation errors in ship motion amplitude do not exceed 5%, and the errors in wave resistance are within 10%. These results indicate that HUST-SWENSE effectively predicts the hydrodynamic interference characteristics between two in-close proximity ships in waves.