Accuracy of Potential Flow Methods to Solve Real-time Ship-Tug Interaction Effects within Ship Handling Simulators

The hydrodynamic interaction effects between two vessels that are significantly different in size operating in close proximity can adversely affect the safety and handling of these vessels. Many ship handling simulator designers implement Potential Flow (PF) solvers to calculate real-time interaction effects. However, these PF solvers struggle to accurately predict the complicated flow regimes that can occur, for example as the flow passes a wet transom hull or one with a drift angle. When it comes to predicting the interaction effects on a tug during a ship assist, it is essential to consider the rapid changes of the tug’s drift angle, as the hull acts against the inflow creating a complicated flow regime. This paper investigates the ability of the commercial PF solver, Futureship®, to predict the accurate interaction effects acting on tugs operating at a drift angle during ship handling operations through a case study. This includes a comparison against Computation Fluid Dynamics (CFD) simulations and captive model tests to examine the suitability of the PF method for such duties. Although the PF solver can be tuned to solve streamline bodies, it needs further improvement to deal with hulls at drift angles.