Numerical analysis of propellers for electric boats using computational fluid dynamics modelling

Abstract

In the maritime industry, propellers are the most commonly used form of propulsion and are core to the optimum performance of a ship. Generally, the performance characteristics of a marine propeller are determined and analysed by experiments like open water and self-propulsion scale model tests which are costly and timeconsuming at the initial design stage. In this study, the computational fluid dynamics (CFD) simulations were performed to evaluate propeller performance. Three Wageningen B-series propellers with varying Expanded Area Ratios (EAR) were modelled with respect to the design constraints, such as ship speed and rotational velocity. The performance of the hydrodynamic coefficients, thrust, torque and open water efficiency are then analysed using the CFD modelling. These characteristics are then validated against experimental data obtained from the Netherlands Ship Model Basin open water test in Wageningen and used to investigate the flow behaviour. The analysis considers the Multiple Reference Frame (MRF) model. This study provided a well-founded framework for applying CFD in the analysis and selection of Wageningen B-series propellers, as well as investigated the relationship between the EAR, flow behaviour, thrust coefficient, and torque coefficient for electric boats. The results show that a lower thrust and torque coefficient can improve the flow behaviour with increasing the efficiency by up to 62%. Furthermore, the outcomes reveal that the lower expanded area ratio of 0.6 is more suitable for electric boats, creating a larger pressure difference of 1.079 MPa and generating extra potential thrust at the same advance ratio, which leads to greater open water efficiency.