Short Crested Wave中の抵抗増加について

抄録

Short crested waves to be generated in our towing tank are two long crested waves superposed, which propagate to two different directions. A model ship running on the centerline of the tank does not oscillate transversely when nodal lines of short crested waves are of even numbers. Added resistance of a ship in such waves could be measured as accurately as in head waves. It seems that added resistance in oblique waves could be approximated by that in short crested waves of even nodes because it is not so much affected by transverse motions of the ship as already shown in several published literatures. In this paper, we present results of experiments on added resistance of a ship as well as its motions in short crested waves. They are compared with the prediction by two theories given by Gerritsma et al. and Maruo et al. Response functions of the ship motions in short crested waves, estimated by using strip theory (O.S.M.) agree well with the measured in our experiments. The two added resistances theoretically computed also agree with the measured except in the range of short wave length, where Maruo's formula shows good agreement with our experiments.