MARIN, the Maritime Research Institute Netherlands enjoys a special reputation even among the elite group of research and testing facilities that global shipping looks to evaluate innovation. Validation in tests at MARIN’s excellent facilities, by scientists, analysts and engineering experts renowned for expertise in hydrodynamic research and maritime technology represents a highly prized industry distinction.
MARIN researchers have recently confirmed to ABB that the performance of ABB Dynafin™ has lived up to expectations predicted by ABB’s earlier CFD modelling of the new concept in ship propulsion. “We would like to congratulate your ABB Dynafin™ team for achieving a very high open water efficiency”, the MARIN researchers wrote. To understand the significance of the results, it is worth recapping what sets ABB Dynafin™ apart as a groundbreaking design, given that the International Maritime Organization target (striving for) an 80 percent reduction in CO2 emissions by 2040 also has significant consequences for ship fuel costs.
“ABB Dynafin™ is all about extremely high efficiency, and this model scale testing gives a good platform for our customers to verify its performance."
Launched after a decade of development1 ABB Dynafin™ is based on the idea of mimicking the whale tail movement, to create the most efficient way to drive ships through water. Rather than a traditional screw propeller, ABB Dynafin™ features a large horizontal wheel mounted in the aft of the vessel, powered by an electric motor to turn at a moderate 30-80 rpm. The wheel is fitted with vertical blades, each of which is controlled by an individual motor to emulate the motion of a whale’s tail.
Combined, the motions of the rotating wheel and the vertical blades simultaneously propel and steer the ship in ways that optimize both thrust and positioning precision. As part of an electric propulsion power system, the concept would fully be compatible with zero-emission battery and fuel cell technologies.
René Bosman, Senior Specialist Mechanical Measurement, MARIN Measurement Systems Image credit - MARIN 
Jie Dang, Senior Project Manager, Principal Investigator, Ship’s Powering, MARIN Image credit - MARIN 
Bin Liu, Senior Principal Scientist, ABB Corporate Research Center, Sweden Image credit - ABB
ABB’s CFD modelling established that ABB Dynafin™ would achieve hydrodynamic efficiency of above 80 percent – a significant improvement compared to any alternative propulsion set-up used in commercial shipping.
In the development phase that resulted in the concept being brought to market in 2023, an independent OSK-ShipTech A/S study concluded that ABB Dynafin™ would save a passenger vessel 22 percent in propulsion energy compared to a conventional shaftline2.
Natural efficiency
A propulsion solution devised to mimic a whale’s tail motion is also one beyond the experience of those specifying shipboard technologies. Bringing hydrodynamic efficiency that took millions of years to evolve in nature to mechanical life has been a task requiring ABB Marine & Ports to leverage wider group expertise in advanced motion control technologies and robotics.
Bin Liu, Senior Principal Scientist, ABB Corporate Research, Sweden, comments: “We have integrated ABB’s leading robotics expertise into the ABB Dynafin™ propulsor, to formulate a strong motion control performance base. On top of that, we have developed ABB Dynafin™ specific motion control solutions – for example to handle hydrodynamic loads. Developing blade motion control has been critical in turning the concept of ABB Dynafin™ into superior propulsor performance in practice. It is quite a technical challenge to control motions at the speeds required, but sufficiently fast dynamics are now possible to achieve high efficiency at transient speeds.”
For MARIN, the verification process has brought the first exposure to ABB Dynafin™. The group of researchers were eager to investigate the efficiency and decarbonization claims made for a truly original ship propulsion concept with full freedom of blade motion.
René Bosman, Senior Specialist Mechanical Measurement, MARIN Measurement Systems, explained some of the intricacies of the power measurement and data analysis required to establish a good overall power prediction for ABB Dynafin™.
“We calibrate the ABB Dynafin™ setup placing a torque and rpm transducer between the main motor and the rest of the system and use a six-component force sensor to predict the overall open water unit forces and moments,” he says. “We also calibrate the friction in blade motors and seals, and measure side forces, bending moments and torque acting on blade motors.”
Jie Dang, Senior Project Manager, Principal Investigator, Ship’s Powering, MARIN, also explained how tests took account of turbulence on the fin models to prevent flow separation and uncontrolled transitions of laminar flow into turbulent flow. “At MARIN, all losses that are due to electrical or mechanical factors of the test set-up are subtracted from the analysis to obtain the hydrodynamic force, so that we can determine pure hydrodynamic efficiency.”
Full-scale validation
The precision provides the basis for a set of results which confirm – just as CFD modelling had predicted – that the propulsor moving at 18 knots would achieve above 80 percent open water efficiency. This is substantially higher than any comparable system used today in shipping.
We would like to congratulate your ABB Dynafin™ team for achieving a very high open water efficiency at about 0.808 for 18 knots operation in full scale.
According to the official communication sent by MARIN to ABB Marine & Ports: "We have high confidence in the results delivered, after more than one week checking all the time signals. These results can be seen as MARIN’s independent validation of your ABB Dynafin™ and hence you can present it to your clients.
“We would like to congratulate your ABB Dynafin™ team for achieving a very high open water efficiency at about 0.808 for 18 knots operation in full scale.”
“ABB Dynafin™ is all about extremely high efficiency, and this model scale testing gives a good platform for our customers to verify its performance,” commented Janne Pohjalainen, Global Product Line Manager for ABB Dynafin™, ABB Marine & Ports. “Our testing has been really successful and what we have seen fully aligns with our expectations from CFD analysis.”
The findings further support the development of a propulsion solution initially focusing on medium-sized and smaller vessels, including ferries, offshore support vessels and yachts – in the power range of 1–4 MW per unit.
According to Pohjalainen, the results provide firm evidence that ships installed with ABB Dynafin™ would achieve the real-world fuel and emission savings its developers projected, as ABB Marine & Ports works towards delivery readiness in 2027. In the meantime, they are also invaluable for optimizing development of a solution whose efficiency gains already point towards ship performance needs being met using less power, smaller engines and lower system capital costs – as well as reduced emissions.
References:
[1] https://new.abb.com/news/detail/103602/abb-unveils-revolutionary-propulsion-concept-to-significantly-increase-ship-efficiency
[2] https://search.abb.com/library/Download.aspx?DocumentID=9AKK108468A2031&LanguageCode=en&DocumentPartId=&Action=Launch
ABB Dynafin™ is a registered trademark of ABB.
