Preliminary Feasibility Study of a Magnetic Levitation Rotor Sail for Coastal Area Operations

The continuous strengthening of environmental regulations is expected to have a significant impact on the vessel operations of shipping companies. Each country must reduce greenhouse gas emissions from ships operating in domestic coastal areas to meet its Nationally Determined Contributions (NDC). For new vessels, we are assessing potential emission reductions through various technologies, recognizing that transitioning to alternative fuels is inevitable to achieve our ultimate goal of zero emissions. However, the introduction of alternative fuels for ships involves numerous challenges, including the overall replacement of propulsion systems, etc. Additionally, to ensure that existing ships can comply with the gradually increasing environmental regulations, the immediate adoption of bridge technologies that can be applied is essential. Rotor sails are recognized as a technology that can be installed on both new ships and vessels in operation, offering carbon emission reductions through thrust assistance. Rotor sails have traditionally been mainly employed on ocean routes with consistent wind patterns. In this paper, we conducted a review of the feasibility of operating rotor sails in coastal areas where wind direction frequently changes and wind intensity is not constant. Particularly, a concept of a rotor sail with magnetic bearings for the rotor sail system, utilizing the principle of magnetic levitation, is suggested. The reduction in frictional forces during rotor sail operation contributes to increased maintainability and advantages in terms of noise and vibration. Specifically, in this study, a structural design for minimizing weight for optimal performance has been carried out.