Case studies on the impact of flap rudders on ship maneuverings

The impact of flap rudders on ship maneuverings is studied in this paper. CFD calculations are performed on both 3D and 2D flap rudders, and a transformation formulation, which can lighten the computational burdens, is proposed to connect the relation of these results. By conducting a series of simulations on flap rudder with different configurations, a flap rudder force model is obtained by regression methods. After that, based on a semi-empirical maneuverability mathematical model, typical maneuvers of a KVLCC2 model equipped with various flap rudders are simulated, while motion parameters during these maneuvers are compared to show how flap rudders affect the maneuverability performance of ships.