A Numerical Study on Sloshing Flows Coupled with Ship Motion—The Anti-Rolling Tank Problem

Abstract

A computational study on the sloshing problem coupled with ship motion in waves is introduced. The ship motion excites the sloshing flow in the ship's liquid cargo, and the slosh-induced forces and moments affect the ship motion in return. This study applies a numerical method to solve the coupling problem of the ship motion and sloshing flow. In particular, it concentrates on the anti-rolling tank, which has the most significant coupling effects of two problems. The three-dimensional sloshing flow has been simulated using the finite-difference method, while the ship motion has been obtained using a time-domain panel method. At each time step, the instantaneous displacement, velocity and acceleration of ship motion have been applied to the excitation of liquid motion, and the corresponding slosh-induced forces and moments have been added to the wave-induced excitation. The computational model is a modified S175 hull, and the computational results have been compared with the experimental data of a supply vessel. Although the two hull forms are not identical, the numerical result for the modified S175 hull shows the same trend of the roll RAOs with experimental data when the anti-rolling tanks are considered. Therefore, the numerical method introduced in this study is expected to be very useful in observing the coupling effects of sloshing and ship motion problems.