Optimal Deck Position of Rotor Sails and DynaRigs for a Bulk Carrier Retrofit Installation

This scientific study aims to compare the significance of onboard positioning of two different classes of wind propulsion systems for retrofit installations to maximize fuel and emissions savings. The study focuses on comparing the performance a low lift-to-drag ratio wind propulsion system, the Rotor Sail, and a high lift-to-drag ratio one, the DynaRig, installed at different places on a real 84000 DWT bulk carrier ship to identify the most efficient placement of these two distinct systems to achieve maximum fuel efficiency. The investigation involves a comprehensive analysis of available deck spaces, and performance prediction program modeling is employed to estimate potential fuel savings for a typical route followed by the vessel. The results show that placing the WPS far forward, close to the hydrodynamic centre of lateral resistance, results in overall higher savings. Both WPS classes see a penalty when placed far from the hydrodynamic centre of lateral resistance, reducing their overall savings potential. However, Rotor Sails are more adversely affected due to their enhanced side force generation per unit thrust. Consequently, the placement of Rotor Sails becomes crucial, especially under upwind conditions, while DynaRigs prove more versatile for installations in the aft. This research provides valuable insights into enhancing the ship's energy efficiency and reducing its environmental impact in the maritime industry.