Alternative methods on added resistance of ships in regular head waves

Abstract

Some selected methods for predicting added resistance of ships in regular head waves have been taken for examination. They are: Maruo’s method, Maruo-Ishii’s method, Gerritsma-Beukelman’s method and Strip method. Three series 60 parent form ships of block co-efficient 0.60, 0.70 and 0.80, representing fine, medium and fuller form ship, have been taken for computation. Computed results are then compared with some available experimental results to examine the suitability of the methods employed. Test and examination results focus in head seas which are the most severe for added resistance. Overall prediction shows that Maruo and Gerritsma-Beukelman’s method may be applied for reasonable prediction, specially for fine and medium ship forms. On the other hand, all the methods mentioned previously (commonly known as 2-D methods) fail to predict reasonable prediction for the fuller ship forms and that is why a 3-D method, which has a wide range of applicability with respect to hull form and frequency, has been applied for the case of fuller ship form.