Hydrodynamic Interactions between Ships in a Fleet

Abstract

There has always been a concern about the hydrodynamic interaction between ships in a flow field. In this study, the RANS method is utilized, and the hydrodynamic interference between two KRISO Container Ships (KCS) operating in still water with identical parameters and sailing at the same speed is investigated. Overlapping grids are used to simulate ship motion, and the VOF method is used to simulate the free surface. A KCS ship model of 1:1 size without propeller is used in the study. In order to study the change principle of the Kelvin flow field created by a single ship, the resistance coefficient and the flow field surrounding the ship are first calculated for the monohull case. Then the influence of interference between two ships is examined at various speeds and intervals and compared with the monohull case. It is discovered that the resistance coefficient of the following ship is reduced in a certain speed interval under the influence of the leading ship, where the maximum reduction can be up to 24.3%. The reason for this phenomenon may be that the wave around the following ship is superimposed on the transverse wave behind the leading ship. When the height of the wave is suppressed, the following ship’s resistance is reduced.

Keywords

• ship fleet
• ship resistance
• Kelvin wake
• wave interference