Numerical study on the de-ballasting operation of a floating dock with a malfunctioning pump

Abstract

In normal de-ballasting operations of floating docks, each ballast pump manages a specific group of ballast tanks, independently of the others. However, if one pump is malfunctioning, a connection valve between the group and its adjacent group is opened, allowing its adjacent pump to control two groups of tanks simultaneously. This study aims to investigate the de-ballasting dynamic process in the event of a ballast pump malfunction by utilizing a numerical model of a full-scale digital floating dock. In the present numerical model, the dock is represented as a rigid body with six degrees of freedom and is subjected to hydrostatic, hydrodynamic, and mooring forces. To maintain pitch and roll angles within predefined limits, a modified P-controller is employed to regulate the valve opening angles at all the ballast tanks. Hydraulic calculations for the ballast water system with a malfunctioning pump are conducted, and the numerical results demonstrate the effectiveness of the present modified P-controller when dealing with a malfunctioning Pump No. 1.