Sensitivity Study of Hydrodynamic Derivative Variations on the Maneuverability Prediction of a Container Ship

Abstract

The study of maneuverability of a ship involves the determination of the hydrodynamic derivatives in the equations of motion. The standard maneuvers are simulated by integrating the equations of motion and the maneuvering parameters are checked for compliance with appropriate standards set by IMO. The numerically or experimentally predicted hydrodynamic derivatives may differ from actual values of the built and operated ship. Hence, it is worth to understand the sensitivity of these variations on the actual maneuvering performance of the ship. This paper deals with a study on the sensitivity of the hydrodynamic derivatives in the equations of motion of a container ship (S175). The sensitivity analysis of all the hydrodynamic derivatives is performed by deviating each derivative in the range of −50% to +50% from the experimentally derived values, in steps of 10%. The standard maneuvering tests like turning tests at rudder angle, δ = 35° and 20°/20° zig-zag maneuvers are performed for each case and their effects on the standard maneuvering parameters are estimated. The hydrodynamic derivatives that are important and which have to be estimated with high level of accuracy in maneuvering studies for a container ship are identified through this study.