Bilge Keel Damping Component Prediction. Comparison of the Simple and Full Ikeda;s Method

Abstract

This paper presents a comparison of the bilge keel component of roll damping, determined by the full Ikeda’s method and its simplified version. The material discusses both procedures for determining the value of the bilge keel component and the calculation results for this component for the general cargo ship are presented. A comparison of the characteristics of value changes of bilge keel damping coefficients in dependence on the relationship of the bilge keel width to its length, while keeping the bilge keel area constant, is presented for two ships with significantly different particulars. Despite the fact that the simplified Ikeda’s method was developed using the regression method for series results obtained by the full method, the calculations made present that the simplified method give comparable results only for small roll amplitudes and small bilge keels areas.

Keywords

• ship rolling
• bilge keel
• roll damping