REDUCTIONS IN ENGINE EXHAUST EMISSIONS IN A HYBRID FLETTNER ROTOR POWER-ASSISTED VESSEL

Abstract

With the increase of Greenhouse Gas (GHG) emissions, the maritime industry has seen an influx of low emission and environmental protection solutions to reduce the GHG-, Hydrocarbon (HC)-, Nitrogen oxides (NOx)-, Sulphur oxides (SOx)-, and particulate matter (PM) emissions. The Flettner rotor is a technology that utilizes wind and the Magnus effect to generate lift for propulsion assist of the vessel. This paper builds on recently reported findings demonstrating the viability of a Flettner rotor propulsion in a hybrid diesel-electric propulsion system for a small cargo ship. Prior related work provided CFD analyses to determine the optimal system architecture in terms of number of Flettner rotors, rotor sizing (diameter, length, etc.), rotation speed and direction, rotor(s) spacing, relative rotor(s) arrangement, etc. Optimal rotor rotational speed was determined to maximize the Lift-to-Drag (L/D) ratios for various geometric rotor configurations. Sample calculations for optimal operating conditions based on Flettner rotor geometry, rotational speed, wind speed, ship’s velocity highlight the potential shipboard power contributions from the operation of Flettner rotor as a power-assist to total onboard propulsive ship power. Estimations of commensurate emissions reductions from engine exhaust (assuming a Diesel-powered main engine) support the estimated environmental benefits of the proposed hybrid Flettner rotor power-assisted propulsion architecture