NUMERICAL ASSESSMENT OF SELF-PROPULSION FACTORS FOR A FAST DISPLACEMENT HULL USING DIFFERENT THEORETICAL APPROACHES

摘要

This work reports the flow analysis in the hull-stern region and the hull-propeller interactions of a Fast Displacement hull using the commercial URANS code CD Adapco Star CCM+- In the present study resistance and selfpropulsion test simulations were conducted to get self-propulsion factors (the wake and thrust deduction factors), using the Computational Fluid Dynamics (CFD) techniques. The computational results were compared with the benchmark towing tank data. The simulation of selfpropulsion test is a non-trivial task for the high speed craft, in particular defining the correct trim and so the correct wake field. The reliability of the results is strictly connected to the high quality of the resistance test simulation and to the propeller-modelling method. The purpose of the current study is to provide reliable and fast results of self-propulsion test simulation for the Fast Displacement hulls. For these reasons, starting from different propeller-modelling method (i.e. the Actuator Disk and the Fully Discretized Propeller) the results were compared in terms of accuracy and computational effort. Furthermore, to take into account the hull motion and the propeller motion the overset mesh technique was employed.