Study on numerical PMM test and its application to KCS hull

Abstract

· A numerical moving tank was applied for the various PMM tests of the KCS model. · Numerical sensitivity of time window, grid resolution, and time step was systematically examined. · The wave patterns and vortices around ship was observed in various PMM test conditions. · A complete set of hull manoeuvring coefficients was obtained. · The manoeuvring coefficients were successfully applied for the prediction of turning tests. The planar motion mechanism (PMM) test is among the most popular methods to evaluate ship manoeuvrability due to its ability to generate manoeuvring coefficients through a series of captive tests. As a replacement for conventional towing tank facilities, the present work applies an open-source-based computational fluid dynamics (CFD) solver to conduct numerical tests, including the static drift, pure sway, pure yaw, and combined drift-yaw tests. The test model is the KRISO container ship (KCS), which has a highly-curved hull with sharp edges and extruded bulbous bow. The original k-ω SST turbulence model has been enhanced to stabilize the turbulence fields near the free surface as well as the hull, and the bow and stern vortices that occur during the ship's PMM motions are displayed in the present CFD analysis. For both the static and dynamic tests, the force and moment predicted by the present CFD solver agree well with the experimental measurements. The numerical PMM tests have generated a complete list of manoeuvring coefficients for the bare hull, and the further application to ship 35° turning circle test has demonstrated a reasonable agreement with the direct free-running experiments.