A berthing ship usually undergoes an unsteady and low-speed lateral motion. Accurate prediction of the viscous hydrodynamic forces on the ship is important to estimate the maneuvering performance of the ship in berthing condition. The flow field around a real ship undergoing berthing motion is very complicated, and the viscous hydrodynamic forces acting on the hull are varying with time during the unsteady berthing process, which is quite different from those for the ship in normal navigation. Especially for real ships, yaw moment and longitudinal force may be remarkable due to the different form at bow and stern part. The focus of the present work is placed on numerical simulation of the viscous flow field and prediction of the unsteady longitudinal and lateral forces and yaw moment acting on a real ship undergoing unsteady berthing motion. A KVLCC2 tanker model is taken as example for the numerical investigation. The unsteady Reynolds-Averaged Navier-Stokes (URANS) equations are solved by using a general purpose CFD code FLUENT with the SST k-ω turbulence model. Detailed flow features at some characteristic time are captured, and the time history of the viscous hydrodynamic forces are presented and analyzed.
Ship berthing is an important phase in the ship's whole navigation process, during which ship's safety and manoeuvring performance are concerned. Therefore, it is of great significance for us to study the flow field and hydrodynamic forces on a ship undertaking berthing motion to ensure a safe operation. A berthing ship usually moves laterally at low speed. In the flow field around a berthing ship, the cross flow is dominant and the viscous effect plays an important role in determining the hydrodynamic forces acting on the hull. Violent flow separation and vortices may be produced in the flow field on the lee side of the hull.