HYDRODYNAMIC DESIGN ASSESSMENT OF ESDs IN STRAIGHT-AHEAD AND DRIFT CONDITIONS
D. Ntouras1, A. Arapakopoulos2, K. Kostalas1, H. Renzsch2, S. Harries2, R. D’Souza1, V. Zagkas1
1 SimFWD P.C., Eth. Antistaseos 14A, 15232 Chalandri, Greece
2 Friendship Systems AG, Benzstr. 2 D-14482 Potsdam, Germany
vzagkas@simfwd.com
Presented at the 20th International Congress of the International Maritime Association of the Mediterranean (IMAM 2025) – Crete, Greece – Sep/Oct 2025
ABSTRACT
Energy-Saving Devices (ESDs) are proving to be increasingly vital in the maritime industry for improving propulsion efficiency and reducing fuel consumption. This study examines the performance of four distinct ESD configurations: three pre-swirl devices and one post-swirl device. In the examined pre-swirl devices, a circular duct, a duct with stator fins, and a duct with half-rings are included, while the post-swirl device is placed at the propeller hub to to absorb the generated vortex. Parametric models were developed using the parametric modelling (CAD) and process integration and design optimization platform CAESES to facilitate a systematic comparison of these designs. Computational Fluid Dynamics(CFD) simulations, conducted with CADENCE FINE/Marine, assessed the influence of each ESD on ship propulsion. A mesh sensitivity study has been carried out to estimate the accuracy of the results, while self-propulsion tests were performed to evaluate the effects of each device on powering performance. Additionally, resistance simulations were carried out to examine the impact of a selected ESD on Wind-Assisted Ship Propulsion (WASP) vessels. The results highlight the crucial role of device geometry in wake flow modification. The findings provide valuable insights for ship designers and operators seeking to implement ESDs for enhanced energy efficiency and reduced emissions.
