LAUSR

There is still room to establish a methodology to optimise marine propellers, considering design requirements of the vessel, and match it to an electric motor. The method proposed herein consists in an optimisation whose objective function is power required in the electric motor shaft, and design variables are the parameters of Wageningen B-screw series propellers. A differential evolution optimisation algorithm was programmed in MATLAB environment to assess a number of propeller designs. Technical constraints of strength, cavitation, and peripheral velocity were considered. An actual ferryboat designed to operate in a lake in south-eastern Brazil is proposed as the case study. The worst individual of the final population of propellers had its objective function increased by 25%, compared with the worst individual of the initial population, within only 123 s processing time. Substantially dissimilar propeller designs were found for direct and geared drive with open water propeller efficiency between 36.18 and 40.49%. The approach has shown significant gains as an early-stage design tool and highlighted the need for exploring a broad range of propellers to find the optimal motor–propeller matching.