Scale effect in the self-propulsion prediction for Ultra Large Container Ship with contra-rotating propellers

This article addresses the problem of the scale effect for an Ultra Large Container Ship (ULCS) with the novel twin-crp-pod propulsion system. Twin-crp-pod propulsion arrangement is an innovative solution that gains from three well-known systems: twin-propeller, contra-rotating propellers and pod propulsor. It is well-known, that the scale effect has been widely investigated for ships with conventional propulsion systems. Nevertheless for ships with the crp-pod propulsion arrangement, due to the combination of shaft propeller and pod propulsor, the problem is a cutting-edge challenge and as such has never been investigated in detail. To address this knowledge gap, CFD numerical simulations in various scales were performed, and this article presents the results of these calculations. The scope of simulations covered self-propulsion tests for a full-scale and model-scale Ultra Large Container Ship in calm water conditions. The model-scale calculations performed at scale 1: 37.416 were validated using towing test results. The self-propulsion simulations have been carried out similarly to towing tank tests following the British method. Calculations were performed for vessel design