Lifecycle Assessment of Fuel Saving in Bulk Carrier With a Flettner Rotor

Abstract

Abstract Reduction of greenhouse gas (GHG) from shipping sector is urgent issue. International Maritime Organization (IMO) adopted the initial strategy on the reduction of GHG emissions from ships. This has accelerated researches and developments on the technologies for energy savings in design and operation stage. A lot of attentions are paid to an application of natural energy to propelling a ship and especially wind propulsion is expected as an effective system for achieving energy saving in operation. This study focuses to a rotor ship as a ship with wind propulsion and addressed a bulk carrier having a rotor onboard. A rotor ship can obtain the thrust force from encountering winds based on Magnus effect and consequently can achieve fuel saving in operation. For spreading the use of a rotor widely, it is necessary to evaluate the fuel saving since the cost for building a rotor ship is larger than that for ordinary ship. For evaluating the fuel saving in a rotor ship with accuracy, the external force such as added resistance in winds and waves should be predicted. For predicting the added resistance, this study applies the methods described in ITTC-RP. The lift and drag force of a rotor is estimated based on the computational studies on a rotating cylinder in uniform flow. Solving the equilibrium equations on the forces acting on a rotor ship navigating with constant speed provides the power-curves in actual seas on which the calculation of fuel oil consumption is based. Furthermore, based on the power-curves and the calculated fuel oil consumption, the lifecycle assessment of fuel saving in a rotor ship, which is considering the effects of aging and fouling for hull and propeller, is conducted. Fuel saving throughout ship’s life based on the lifecycle assessment is reported in this paper.