A system-based approach to estimate manoeuvring performance of naval ships supported by captive tests in regular waves

The investigation of the manoeuvring performance of naval ships in regular waves is conducted using a system-based approach and captive tests in waves. The methodology involves experimentally investigating the naval ship model – Office of Naval Research's (ONR) Tumblehome – in different wave conditions at zero speed with heading angles ranging from 0° to 180°. The data reduction procedure extracts second-order mean wave drift loads—specifically surge and sway forces and yaw moment—from the measurement data. Experimental results of these loads are compared with empirical and computational results. Wave loads obtained experimentally are used in the equations of motion, leveraging the modular nature of the Manoeuvring Modelling Group's (MMG) standard method. Turning circle trajectories and secondary parameters are studied in both calm water and waves. Another approach, which directly employs time series measurements in the MMG model, is also explored. The research shows that the modular approach, supported by experimental measurements in waves, significantly enhances the predictive capability of system-based models. The limitations of this approach in predicting the behaviour of naval ships in waves are demonstrated through comparisons with free-running test data.