Experimental analysis of resistance reduction and heel motion characteristics of wind-assisted vessels using the SIL system

In response to the recently strengthened regulations by the International Maritime Organization (IMO) concerning the Carbon Intensity Index (CII), there is a growing need to adopt alternative propulsion technologies to reduce fuel consumption and carbon emissions. In this context, wing sails, as one of the wind-assisted propulsion systems, are gaining attention as an eco-friendly solution to enhance ship fuel efficiency. However, their practical implementation requires a comprehensive assessment of their influence on ship stability under diverse sea conditions. To address this gap, this study experimentally evaluates the resistance reduction and roll motion characteristics of wing sail vessels under various marine environmental conditions using the Software-in-the Loop (SIL) method. In the present study, the SIL method creates a closed-loop system where the aerodynamic forces generated by wing sails are simulated as virtual forces and updated in real-time based on the measured motion of the vessel. As a result, the wing sail achieved a maximum resistance reduction of 33%, while the lateral force induced by the wing sail caused a maximum heel angle change of 0.6°. Furthermore, in terms of trim and sinkage, the wing sail showed a tendency to reduce trim, whereas sinkage remained unchanged. • SIL method developed to measure real-time wing sail performance in towing tank tests. • Wing sail aerodynamics were implemented by dynamically adjusting forces based on ship motion. • Wing sails achieved 9.26% to 33.23% drag reduction across various wind conditions. • Heel motion was measured to evaluate wing sail stability on container ships.