A Simple Prediction Formula of Roll Damping of Conventional Cargo Ships on the Basis of Ikeda＇s Method and Its Limitation

作     者：Yuki Kawahara Kazuya Maekawa Yoshiho Ikeda 

作者机构：Department of Marine System Engineering Osaka Prefecture University Sakai 599-8531 Japan 

出 版 物：《Journal of Shipping and Ocean Engineering》 (船舶与海洋工程（英文版）)

年 卷 期：2012年第2卷第4期

页      面：201-210页

学科分类：0820[工学-石油与天然气工程] 08[工学] 0824[工学-船舶与海洋工程] 082002[工学-油气田开发工程] 082401[工学-船舶与海洋结构物设计制造] 

主　　题：Roll damping simple prediction formula wave component eddy component bilge keel component. 

摘      要：Since the roll damping of ships has significant effects of viscosity, it is difficult to calculate it theoretically. Therefore, experimental results or some prediction methods are used to get the roll damping in design stage of ships. Among some prediction methods, Ikeda＇s one is widely used in many ship motion computer programs. Using the method, the roll damping of various ship hulls with various bilge keels can be calculated to investigate its characteristics. To calculate the roll damping of each ship, detailed data of the ship are needed to input. Therefore, a simpler prediction method is expected in primary design stage. Such a simple method must be useful to validate the results obtained by a computer code to predict it on the basis of Ikeda＇s method, too. On the basis of the predicted roll damping by Ikeda＇s method for various ships, a very simple prediction formula of the roll damping of ships is deduced in the present paper. Ship hull forms are systematically changed by changing length, beam, draft, mid-ship sectional coefficient and prismatic coefficient. It is found, however, that this simple formula can not be used for ships that have high position of the center of gravity. A modified method to improve accuracy for such ships is proposed.