Abstract
In reference to the estimation method of drifting force acting on a floating body in waves, Tasai pointed out a problem about the disagreement between theoretical and experimental results. In Tasai's paper, however, the theoretical results by Maruo in the two-dimensional case were discussed by quoting the experimental ones by Suyehiro and Tasai obtained for the three-dimensional bodies. To look into the pertinent disagreement, therefore, it will he necessary to make detailed investigations into difference in the two- and the three-dimensional problems. In the present paper, the author carried out an investigation to ascertain the validity of the evaluation of drifting force based on Maruo's theory, confining the problem to two-dimensional cases. The two-dimensional experiments were conducted for two models; a semi-immersed circular cylinder and a catamaran hull composed of semi-immersed circular cylinders. Comparisons were made of the measured results with the theoretical predictions based on exact treatment of the linear potential theory. Calculated results were all in fairly good agreement with the measured ones. From these results, it is inferred that the cause of the disagreement pointed out by Tasai may be due to the effect of the three-dimensional motion of fluid. In order to clarify the problem, therefore, studies on the three-dimensional problems such as the one by Kudo will be called for.
