An Investigation of Rolling-Motion Reduction for a Floating Body in Waves

Abstract

In this paper several aspects of roll stabilization of a floating body in beam waves will be discussed. The equations of rolling motion including coupling effects with swaying motion are given, in which wave-exciting moment is represented by effective wave-slope coefficients (γ). The diagrams to evaluate the γ coefficients readily, are presented for box-shaped floating bodies. According to the diagram, it might be possible to make the γ coefficients zero at any desired wave frequency, by adjusting the position of the center of gravity of floating bodies. Numerica1 computations of rolling motion for the box-shaped floating body with the adapted center of gravity, shows significant reduction of rolling motion. Subsequently, new design consideration for Anti-Rolling Tank (A.R.T.) by using the present equations of motion are proposed. It is also shown .A.R.T. is a practicable device for roll stabilization of box-shaped floating bodies with shallow draft.