抄録
For predicting ship manoeuvring performance, it will be very important to estimate the hydrodynamic forces acting on a ship with high accuracy. The hydrodynamic forces can be estimated by the approximate formula as a function of principal particulars of the ship. However, it will be not able to estimate the hydrodynamic forces considering the detail hull form such as a frame line by using this prediction method. Therefore it is necessary to establish the prediction method which can be took into the effect of difference of frame line configuration in order to estimate the hydrodynamic forces more accurately. In the last paper, we examined the hydrodynamic forces acting on a ship hull in oblique motion considering the frame line configuration by using the prediction method which was based on Fuwa's method. Because of the assumption of the separation line which was set on the keel, we couldn't get a qualitative agreement between the estimated hydrodynamic forces and the measured hydrodynamic forces in manoeuvring motion with large drift angle. In this paper, we investigated the hydrodynamic forces acting on three types of model ships which were a VLCC with V type-frame aft part, a VLCC with U type-frame aft part and a VLCC with just middle frame line configuration between V type and U type. We assumed the separation line on both starboard bilge and port bilge referred to the results of captive model tests and shed the vortex lines freely. From the results of numerical calculation in the proposed method, we got the following concluding remarks. As a result of the comparison between the estimated hydrodynamic forces and the measured hydrodynamic forces, we got a good agreement in these results. Furthermore, it is considered that it will be able to estimate the hydrodynamic forces acting on a ship hull in oblique motion taking into the frame line configuration with high accuracy by using the present method.
