A common problem in numerical simulations is finding the correct parameter values of a mathematical model. A typical example from MARIN practice is the simulation of a ship manoeuvre, like a zig-zag or a turning circle (Figure 1), where the result is compared with the outcome of an experiment. The forces acting on the ship
Introduction ‘Parametric roll’ is a phenomenon that sometimes suddenly occurs to ships sailing in the head or following seas. Apparently, without any clear reason, the amplitude of the roll motion (i.e. the rotation about the longitudinal axis of the ship) increases within a couple of roll periods, from a few degrees to above 45 degrees.