Analysis of a Single Squared Wingsail Design as an Auxiliary Propulsion System on a Tanker Ship

This study presents an analysis of a single squared wingsail used as an auxiliary propulsion system for an 8,700 DWT oil tanker. The objective is to evaluate the aerodynamic performance and stability feasibility of the wingsail and to assess its contribution to engine power reduction. Numerical simulations were conducted to obtain lift and drag coefficients for three aspect ratios (AR 2, 4, and 6) with a constant sail area of 289 m2. Stability assessment was performed at multiple voyage waypoints along the Gresik–Bontang round trip using the weather criterion (K ≥ 1) and metacentric height (GM ≥ 0.3 m). The results indicate that all configurations satisfy the stability requirements, while AR 4 provides the most effective performance in terms of thrust generation and power reduction. The AR 4 configuration, with a span of 34.0 m and a chord of 8.5 m, achieves the highest average engine power reduction of 5.3%, compared to 4.9% for AR 2 and 4.1% for AR 6. These findings demonstrate that the selected wingsail configuration is aerodynamically effective and stable, offering a practical solution for auxiliary wind-assisted propulsion on tanker vessels.