A Practical Approach to Numerically Predicting a Maneuvering Vessel in Waves Oriented to Maritime Simulator

Abstract

To improve the behavioral realism of maritime simulator, the mathematical model of ship heave and pitch motion in regular waves is proposed. To avoid the influence of irregular frequency by two-dimensional Frank source and sink distribution method, the multiparameter conformal mapping method was adopted to solve the hydrodynamic problem of ship’s transverse sections, and then the integration of the hydrodynamic coefficients and the wave exciting forces for the whole ship hull was obtained using the Salvesen–Tuck–Faltinsen (STF) strip method. The Abkowitz model was used for the horizontal maneuverability motion equations, and the ship heave and pitch motion mathematical model in regular waves can be built considering the maneuvering factors. To verify the credibility and applicability of the improved model, the Mariner vessel with a Froude number of 0.2 was taken as the simulation case; when Mariner vessel sails in head waves, the maximum relative error between the calculated results and the experimental results is 23.6% for amplitude response operators of ship heave and pitch motion, and the calculated results and the experimental results have the same trend. When turning maneuvers in regular waves are carried out, the time history of ship pitch and pitch motions in regular waves does not show the sinusoidal periodic change any more, but the time history of heave and pitch motion still possesses periodic change to some extent, at which the period is about the time required for the turning motion to finish a circle. When turning maneuvers are carried out for 3000 seconds, the time required for computer operation is about 487.6 s, and the real-time requirements of maritime simulator are satisfied. Thus, the mathematical model of ship heave and pitch motion established in this paper can be effectively applied to the maritime simulator.

Simulation of Turning Manoeuvre of Planing Craft Taking Into Account the Running Attitude Change in a Simplified Manner

“…Taimuri et al [5] presented a modular mathematical model and a technique for the estimation of manoeuvring trajectories and motion time histories of single and twin-screw propulsion ships, in which MHCs should be extracted from PMM tests or semi-empirical relations. Ni et al [6] proposed the mathematical model for heave and pitch motion in regular waves to improve the manoeuvring behaviour of a maritime simulator. The multi-parameter conformal mapping method was adopted to solve the hydrodynamic problem of ships' transverse sections The integration of the hydrodynamic coefficients and the wave exciting forces for the ship hull was then obtained using the strip method.…”