Determination of ship maneuvering performance with system based approach

In this study, system based simulation methods were utilized to determine maneuvering performances of two tankers which have U and V stern forms. By the representation of lateral force and yaw moment with second and third order polynomials; six different mathematical models with three degrees of freedom based on MMG (Maneuvering Modeling Group), Abkowitz and Blanke concepts were utilized. Hydrodynamic coefficients and related parameters of the two hulls KVLCC1 and KVLCC2 in mathematical models were estimated by using the straight line test, circular motion mechanism test and planar motion mechanism test experimental data of NMRI (National Maritime Research Institute, Japan) and MOERI (Maritime and Ocean Engineering Research Institute, Korea). Turning circle (±35ᴼ), zigzag (±10ᴼ/±10ᴼ) and zigzag (±20ᴼ/±20ᴼ) maneuvering motions were simulated for models with captive model tests and free model tests, and full scale hulls of both KVLCC1 and KVLCC2 with three different hull dimensions and compared with the free test experimental data of MARIN (Maritime Research Institute Netherlands). Additionally, as a result of sensitivity analysis, mathematical model of Mariner hull was simplified and performance of iterative solution algorithm used in grey box method, which is one of the system identification methods, was presented. The problem, which occurs particularly in full scale hull simulations, with the disagreement of both turning and zigzag maneuvering together in simulations based on experimental methods has been overcome by utilization of hydrodynamic coefficients and parameters re-estimated with grey box method.