Evaluation of Push-Pull manoeuvring mode for a naval ship using CFD

Enhanced manoeuvring capabilities are critical for modern warships, as they directly impact mission success and defensive operations. Various strategies have been proposed to improve a ship's manoeuvrability, including the use of bilge keels and fin stabilizers. This study investigates the application of the Push-Pull mode—a manoeuvring technique that uses both pushing and pulling propellers—as a potential means to enhance overall manoeuvring performance. While this mode is typically employed in docking operations, its effectiveness in general manoeuvring scenarios remains largely unexplored. To assess its impact, a free-running manoeuvre model for the fully appended Office of Naval Research Tumblehome (ONRT) hull was developed using the Unsteady Reynolds-Averaged Navier-Stokes (URANS) method. The ship's performance was evaluated through both turning circle and U-turn (turning back) manoeuvres under two configurations: Push-Pull mode and the conventional rudder-only method. Simulation results demonstrated that the Push-Pull mode significantly enhanced manoeuvrability in both manoeuvre types, indicating its potential applicability beyond docking scenarios.