The hydrodynamic forces of a Container ship in oblique motion considering ship sinkage and trim was predicted using RANS simulations. Numerical simulations were carried out using CFD for KRISO Container ship (KCS) with respect to drift angle and velocity. The simulation results show good agreement with the experimental results. The results conclude that the dynamic drift of ship at high velocity has an effect on lateral force and yaw moment in oblique motion. In dynamic drift, the lateral forces at different drift angles shows a nonlinear relationship, but yaw moments still keep a linear relationship. The results can be used to ensure the maneuverability of the ship during the oblique voyages, prevent yaw and improve the directionality.
Good maneuverability is essential for ship navigation safety. That is important for hydrodynamic forces research acting on the ship in the form of oblique motion for study ship's maneuverability. For added safety and reliability. Traditionally, test ship oblique motion maneuverability is always using model tests, which are both costly and time-consuming. However, in many past studies, the ship's trim and sinkage were often overlooked, but with the development of the computer computing power and increasing of different CFD tools, it is a better measure of the impact of these two coefficients of maneuverability of the ship. In order to accurately predict the maneuvrability of the ship during oblique motion, verify the reliability of CFD in dynamic oblique motion simulation, and explore the difference between the maneuverability results of static condition and dynamic condition, it is necessary to perform dynamic oblique motion simulation.
Reliable hydrodynamic forces is an essential part of accurate prediction of oblique motion maneuverability. Traditionally, methods to predict the hydrodynamic forces of an ocean vehicle could be categorized into three types: potential based method (Sahin et al., 1997), the semi-empirical method (Geisbert, 2007), and the experimental method (Avila and Adamowski, 2011), (Park et al., 2017). But now, CFD has been applied as an important way in recent years to determine the hydrodynamic forces of oblique motion maneuverability. Pan et al. (2012) calculated hydrodynamic damping coefficients of the (SUBOFF submarine model, 1989) by simulating oblique towing and PMM tests.