ActiveRudder – Innovative Propulsion and Manoeuvering System 2023 – 2025

The European Union’s “Green Deal” aims for the EU to achieve climate neutrality as an economic region by 2050. To this end, greenhouse gas emissions from transportation are to be reduced by 90%. Additionally, there are port authorities that offer fee discounts to ships entering with lower exhaust and/or noise emissions.

The outlined boundary conditions highlight the necessity for the maritime industry to develop solutions for the anticipated retrofitting of existing fleets and the construction of new vessels. One solution is to develop an auxiliary propulsion system for ships that relies exclusively on alternative green energy sources, such as hydrogen-powered fuel cells, and is suitable for both retrofitting and new builds. This could involve installing a self-contained electric sub-network with onboard fuel cell(s) to power an active rudder. The propulsion capacity of the active rudder should be sufficient for ships to navigate canals, enter ports, and manoeuver there using this system alone, without relying on the main diesel engine. The energy source should also be designed to supply the ship’s onboard power network during these phases, allowing the diesel generators to be turned off as well. This would ensure that all CO2 emitters and low-frequency noise sources are deactivated, addressing not only exhaust emissions but also underwater noise, which is a growing focus of the IMO (International Maritime Organization). The active rudder is intended not only to significantly improve the ship’s maneuverability but also to provide redundancy in propulsion and steering through the independence of the energy source, thereby enhancing safety and functionality. During transit, the auxiliary propulsion system can be used as a booster, allowing the main diesel engine’s output to be reduced by this amount of power without compromising service speed. As part of the research topic, SVA contributes to this development with its expertise in fluid dynamics design of propulsion systems and their testing at the model scale. This contribution includes detailed investigations of flow patterns and noise generation. In addition to the fluid dynamic design of the auxiliary propulsion system, which consists of a rudder, active rudder propeller, and nozzle for various types of ships, the focus is on the hydrodynamic and hydroacoustic optimization of the entire system, which includes both the main propulsion and the active rudder. The system will be tested through extensive model trials (free-running, propulsion, maneuvering, cavitation tests, and acoustic measurements).