Performance analysis of Flettner rotor considering Marine wind profile and ship installation using CFD

Abstract

The study investigated a Flettner rotor performance on a hull, analyzing design modifications and wind profiles for a small catamaran which designed by KRISO for the K-Energy Observer platform was analyzed. The rotor mounted on the hull showed a nearly 48% performance degradation in lift coefficient compared to the standalone rotor due to the disturbed flow by the hull at spin ratios 3–4. Two design factors were examined to improve performance: foundation shape and bottom configuration of the rotor. A square foundation shape showed relatively better improvement but it was not significant. On the other hand, it was found that the rotating end plate significantly improved thrust, achieving up to 80% of the standalone rotor’s performance. Comparing uniform and Norwegian Petroleum Directorate (NPD) wind profiles, the NPD profile showed a 12% improvement due to stronger winds at the rotor’s upper section. The study also compared performance under different wind directions and it showed a 20% increase at 30° and 18% at 60° for the original configuration. In contrast, the rotating end plate configuration showed a 6% decrease at 30° but a 10% increase at 60°. However, overall performance improvement was observed in the rotating end plate configuration with increases of 12%, 34%, and 44% for 30°, 60° and 90° compared to the original configuration. Additionally, under a 5° inclined hull condition, performance decreased by 21% for the original configuration but only 13% for the rotating end plate configuration, which highlighted the design’s effectiveness in mitigating performance loss.