Aerodynamic analysis of segment rigid sails and estimation of propulsive power from sail array on large powered ship

Although not in widespread use today, rigid sails installed on ocean-going powered ships could potentially lead to reductions in fuel oil consumption and polluting airborne emissions including greenhouse gases (GHG). Despite their potential though, there is limited literature available regarding the aerodynamic analysis of rigid sails, the use of rigid sails arranged as an array and the modelling of the fuel consumption reductions that might be possible. This research project therefore studied the airflow around a rigid sail and rigid sail array using a virtual wind tunnel and a Computational Fluid Dynamics (CFD) software application. A new rigid sail design designated as a segment rigid sail (SRS) was also created. This formed the basis for constructing 3D computer models that were subsequently used as the baseline for the analysis of power from an SRS array. Additionally a 3D computer model of a concept ship specially designed to be fitted with rigid sails was created and airflow around the 3D ship model (Eco Ship) was also observed. Furthermore a methodology for creating a rigid sail power profile was created, and a model for estimating the potential propulsive power a sail array could provide and the associated reduction in fuel oil consumption developed. A review of various aspects related to the installation and operation of rigid sails on powered ships was also undertaken and this took into account engineering, operational and economic considerations. This project found that a single SRS with a sail area of 102 m\\(^2\\) and an aspect ratio (AR) of 1.6 could potentially provide up to 171.6 kW of propulsive power on a ship operating at 12 knots with the apparent wind speed being 35 knots. It was also determined that an SRS array with 14 sails and a total sail area of 1400 m\\(^2\\) could provide approximately 47% of main engine power (P\\(_{ME}\\)) for an Eco Ship if the vessel was operating at a low speed and strong winds were present. Using typical operational profiles for a bulker, propulsive power from the sail array (P\\(_{SA}\\)) was found to provide between 1.7% to 7.7% of main engine (M/E) power on voyages lasting several days during which wind conditions and the ships speed varied. Analysis conducted during the project also indicated that there was scope to improve the performance of multiple sails arranged in an array by adjusting their spacing, orientation and rotation either together as an array, or potentially adjusting the position of each sail individually via an automated control system.