Report on Comparative analysis of advanced screw propulsion studies

This report presents the analysis and discussion of computational and experimental results obtained in Work Package 21 of the STREAMLINE Project for the optimization of State-of-Art screw propulsion systems. During Work Package 21 activity, computational and experimental studies have been performed to investigate the capability of advanced Computational Fluid Dynamics (CFD) models to determine optimised propulsion layout solutions that are able to improve current standards for propulsive performance of a target vessel type. In parallel, model tests have been devoted to characterise the performance of the optimised configurations in order to quantify improvements versus a reference layout. All design and optimization studies have considered as a common baseline the STREAMLINE Tanker, a 7000 DWT single-screw vessel representative of small-size low speed vessels populating European sea routes for the shipping of goods. Optimised layouts include both retrofit solutions as well as alternative ship designs by hull shape optimization. Specifically, a new hullform and two new propellers have been designed. Two twisted rudder designs have been proposed and four alternative energy saving devices have been developed: pre-swirl stators, vortex generators (two layouts), and boundary-layer alignment ducts. Project report Deliverable D21.14 presents the results of the comparative analysis with retrofit solutions.