Determination of Hydrodynamic Derivatives

The prediction of manoeuvring performance in the early stages of ship design is often done by determining the hydrodynamic derivatives by various methods including those based on potential theory. Strip theory, slender body theory and conformal mapping are used to determine added mass and inertia coefficients. Hull hydrodynamic derivatives may be calculated using slender body theory and low aspect ratio wing theory. Rudder derivatives and derivatives due to a longitudinal fin attached to the hull may also be determined. Empirical methods based on model test data are available. Two other methods, System Identification and Computational Fluid Dynamics, are considered briefly.