0n Roll Damping Force of Ship : Effects of Hull Surface Pressure Created by Bilge Keels

Abstract

The roll damping force of bilge keels consists of two components, one due to the normal force acting on bilge keels and the other due to the hull pressurecreated by bilge keels. Measurement of the hull pressure for several two dimensional cylinders with bilge keels were carried out. On the basis of these experimental results, a formula for roll damping coefficient due to the hull pressure component is proposed. And the estimated values of roll damping coefficient due to bilge keels which are derived from this formula together with the formula for the normal force component recently proposed by the authors, show fairly good agreements with experimental values for two dimensional cylinders and ship models with bilge keels.