A number of locks have been under consideration or construction in recent years. The growing number of large vessels can only be used if sufficient infrastructure, like locks, is available. Especially for large vessels that are most critical, the hydrodynamic phenomena induced by a lock entry are important, since the ship’s movements are strongly influenced by those phenomena.

For a better understanding of the mechanism of the ship behavior and the effects of eccentricity on the ship behavior while entering a lock, the unsteady viscous flow around the 12000TEU ship model while entering a lock with different eccentricity is simulated and the hydrodynamic forces, vertical displacement are calculated by solving the unsteady RANS (Reynolds Averaged Navier–Stokes) equations in combination with the k-ω SST turbulence model. Overset grid technology is used to keep grid orthogonality. To make our prediction more reasonable, the effects of the free surface is taken into account. A benchmark test case is designed first to validate the capability of the present methods in the prediction of the viscous flow around the ship when maneuvering into the lock. Accumulation of water in front of the ship during entry into a lock is noticed, which causes the increase of the velocity of the return flow. A set of systematic computations with different eccentricity are then carried out to examine the effect of eccentricity on the ship-lock hydrodynamic interaction while entering a lock. With larger eccentricity, higher lateral force and higher yawing moment is observed, which cause greater risk of contact of a ship with the lock infrastructure.