抄録
From the viewpoint of marine safety, it is of importance to grasp ship manoeuvring performance, such as berthing in a harbour, drifting behaviour of a disabled ship. For the prediction of ship manoeuvrability with high accuracy, it will be required to estimate the hydrodynamic forces acting on a ship accurately not only in relatively high speed motions with small drift angle but also in low speed motions with large drift angle. So, numerical calculations have been already given to the longitudinal distribution of the cross flow forces over the length of ship at larger drift angles. This theoretical method is on basis of vortex shedding model developed by the authors. The numerical results for a container ship hull in drifting motion agree well with measured results of oblique towing model test. In this paper, the simulation calculations based on the mathematical model are compared with the results of free running model test for typical manoeuvres with tugboats. The hydordynamic forces acting on ship, which are needed for the numerical simulation of manoeuvring motion, are obtained by means of theoretical method. Form these studies, it is found that this approach will be useful for parctical prediction of manoeuvrablily for ship in low speed motions at early design stage. However, there still remain some problems to be solved, such as the effect of yawing motion on hydrofynamic forces acting on ship in large drifting motion, to perdict the manoeuvring performance more accurately.
