•  
  •  
 

Abstract

The Flettner rotor is a wind-assisted propulsion system applied in eco-friendly ship to reduce greenhouse gas emissions. As the requirements of international regulations on greenhouse gas emissions become increasingly strict, multiple Flettner rotors are being applied, necessitating the evaluation of their performance with varying design parameters. The present study focuses on the aerodynamic performances of four Flettner rotors with variable design parameters of distance and spin ratio. Distances and spin ratios, including relative spin ratios, are considered. The drag and lift coefficients and lift-to-drag ratio of Flettner rotors are determined using Computational Fluid Dynamics (CFD), and the associated flow fields are assessed. It is confirmed that the windward Flettner rotor shows better aerodynamic performance compared to the leeward Flettner rotor at constant spin ratio for all Flettner rotors. The aerodynamic performance of the leeward Flettner rotor proves to be sensitive to variations in distance and spin ratio, which are attributed to the deflected and unstable flows occurring downstream of the windward Flettner rotor. The effects of spin ratio and distance on total drag and lift coefficients and lift-to-drag ratio are also investigated. The findings of the present study have the potential to enhance the applicability in the design and operation of Flettner rotors. The additional assessment of the performance of Flettner rotors under different design parameters and number of Flettner rotors can be supplemented through future research.

COinS