A STUDY ON MULTI-BODY FLOATING SYSTEM IN FINITE WATER DEPTH BY SEPARATE REGION METHOD
Yoshiyuki Inoue and Xuangang Zhang, Yokohama National University, Yokohama, Japan
ABSTRACT
The research on multi-body floating system has been carried out by many researches in recent days because of its increased practical uses. In these researches, almost all, three-dimensional source method is applied. In this paper, a relatively simple but effective method, separated region method, is applied for predicting the responses of multi-floating bodies in finite water depth. For afloating rectangular section in the finite water depth, the separated region method (eigenvalue method) is very useful to predict the hydrodynamic forces on the body. The method has been extended here, so as to apply to the problems of multi-floating bodies. To check the validity of the method, motion responses of two floating bodies were calculated and the results were compared with experimental data carried out by M. Ohkusu (1976) and M. Kubo et al. (1989). The agreements between the theoretical and the experimental results of motions of two floating bodies are fairly well. Moreover, the influence of a floating breakwater on the floating body and the property of multi-floating breakwater system are discussed in this paper by use of the method.
THE MEAN DRIFT FORCES AND YAW MOMENT ON MULTI PLE-CYLINDERS IN WAVES AND CURRENT
Takeshi Kinoshita and Weiguang Bao, Institute of Industrial Science, University of Tokyo 7-22-1 Roppongi, Minato-ku, Tokyo, 106 Japan
Shunji Sunahara, Department of Ocean Engineering, University of Tokai, 3-20-1 Orido, Shimizu, Shizuoka, 424 Japan
ABSTRACT
In the present work, the interaction of an assembly of circular cylinders with regular waves and slow current is considered. The interaction among cylinders is represented by additional waves emitting from adjacent cylinders towards the cylinders under consideration. By means of eigenfunction expansion, drift forces, as well as yaw moment, are evaluated by the far field method and the wave drift damping is deduced from these results semi-analytically. The contribution from the second order steady potential which is quadratic in wave amplitude is also considered. Calculated examples are presented in various wave direction. Those results are also compared with experimental measurements to verify the present theory.
