Research

Title:	Acoustic prognoses for route and operating profile optimization
Term:	2025 – 2027
Project manager:	Rhena Klose
Funding:	Bundesministerium für Wirtschaft und Klimaschutz
Project administration:	EuroNorm GmbH
Reg.-No.:	49VF240046

As part of the preliminary research, the project aims to provide a concept and the tools by which an acoustic route and operating profile optimization for ships can be implemented. The aim is to dynamically determine the individual noise output put of a ship in order to enable noise reduction through active route or driving profile adjustments right during operation. In addition to the goal of noise reduction, economic aspects such as fuel consumption and operating costs must also be considered, taking into account travel times and current environmental conditions.

By achieving this goal, the anthropogenic impact on marine life due to noise emissions from commercial shipping can be minimized by changing sailing behaviour and the protection of marine life can be ensured. The AkuOpt project lays the foundation for this and serves to demonstrate practical measures for noise reduction in ship operations. These noise-reducing operational measures are to be identified through targeted research in the field of structure-borne and water-borne noise as well as the analysis of environmental conditions and operating profiles.

The noise emissions caused by ships are to be determined and specific recommendations made for noise-reducing measures during operation, such as changing the operating point or taking alternative routes. This includes the development of an algorithm for an acoustic prognosis tool for ships, which provides information on whether protected areas may be passed through depending on the local conditions or how much the speed must be reduced in order not to exceed certain noise levels.

In order to be able to calculate alternative operating conditions or routes, the noise emissions of a ship under certain environmental influences must be known. This requires the determination of the currently emitted sound levels in near real time. This can be done, for example, with sound monitoring systems already available on board or with an acoustic forecasting tool that calculates the current sound emission based on a small amount of input data. Both approaches are to be investigated in the research project.

Title:	WIND – Development of test methods for wind-assisted seagoing vessels
Term:	2024 – 2026
Project manager:	Martin Börner
Funding:	Bundesministerium für Wirtschaft und Klimaschutz
Project administration:	EuroNorm GmbH
Reg.-No.:	49MF240089

Since wind is a boundary condition that cannot be influenced and depends heavily on, for example, the time of year and the operating area, it can be useful to specify power prognoses in a polar diagram based on variable wind vectors. Such a prognosis diagram enables the identification of efficient and avoidable operating conditions for the wind propulsors. Unfavorable wind conditions can lead to significant drift angles, which in turn can result in significantly increased hull resistance and additional steering resistance. Furthermore, efficiency losses on the propeller due to oblique flow must be expected.

The creation of a performance prediction for seagoing vessels with the integration of wind propulsors is therefore based on the determination and consideration of all relevant variables that are a direct consequence of wind propulsors. In order to scale these variables as correctly as possible, test and evaluation procedures must be developed. The procedures provided by the ITTC for the preparation of speed and power prognoses are based on idealized conditions and assumptions such as no drift, smooth and deep water conditions. There are currently no ITTC-validated prognosis procedures that take into account the use of wind propulsors under normal propulsion conditions.

Within the scope of this research topic, two methods for conducting and scaling experiments are to be investigated. On the one hand, the free-moving model is to be investigated taking into account defined wind vectors. For this purpose, the model will be equipped with a wind propeller as a replacement system for the wind actuator and a second wind propeller for the friction deduction force to be applied. The model test thus simulates a model of reality that is as physically fully scaled as possible. A second method examines the tethered model. This method is based on the load variation method, whereby the wind force and the friction penalty are part of the measured residual drag force as a function of a defined drift angle.

Title:	A-SWARM II – Autonomous electric Shipping on Waterways in Retropolitan Region
Term:	2024 – 2027
Project manager:	Kay Domke
Funding:	Bundesministerium für Wirtschaft und Klimaschutz
Project administration:	Projektträger Jülich
Reg.-No.:	03SX593A

Particular attention will be paid to the optimization and expansion of the individual demonstrators, and the coupling system will also be investigated for the first time.

A central element of the project is the development and testing of technologies for fully autonomous operation, including:

• Autonomous navigation under difficult conditions, such as uncertain weather,
• Safe passage of bridges and locks in swarm operation,
• Consideration of variable load conditions and their effects on manoeuverability,
• Goods handling with automated demonstrators to enable unmanned operation.

The vehicles are to be optimized so that they operate in an energy-efficient manner, among other things by precisely calculating steering forces in advance. At the same time, the vehicles from the “DigitalSOW” project will also be coupled and the entire coupling system will be tested as a complete system for the first time. Challenges such as data transmission between the vehicles and the synchronization of control systems are also being addressed.

In the long term, the project will help to integrate waterways more closely into transport networks – especially for city logistics. The congestion on roads and railways makes it urgently necessary to shift freight traffic to alternative transport routes. Swarm technology with electric drives offers a forward-looking solution for this, as classic inland waterway vessels are not suitable for modern logistics tasks such as general cargo transportation or recycling management, particularly in metropolitan regions, due to their size and inflexibility.

Through these further developments, the project is making a key contribution to the sustainable transformation of goods logistics on water.

Title:	KonRo – Design and Optimization Tool for a CRP Propulsion Concept
Term:	2024 – 2026
Project manager:	Katrin Hellwig-Rieck
Funding:	Bundesministerium für Wirtschaft und Klimaschutz
Project administration:	EuroNorm GmbH
Reg.-No.:	49MF23104

Not only the energy savings but also improved maneuverability and, depending on the propulsion concept, a potential increase in safety compared to single propellers — due to the redundancy provided in case of a propeller failure — make the CRP an attractive option for main propulsion systems. The arrangement of the TWIN-CRP at the aft ship is identical to that of a single propeller. The application of CRP systems is primarily seen in specialized vessels, such as fishing vessels, research ships, and supply vessels.

Through its R&D project, the SVA aims to develop a reliable approach for the design and optimization of contra-rotating propellers with a dual-shaft system and minimal spacing between the two propellers. Based on CFD simulations, which will be validated through laboratory experiments during the project, the accuracy of performance predictions for ships equipped with the above-described CRP propulsion system is to be improved. To achieve this, the accuracy of numerical methods must be further improved for both design and off-design conditions. In the past, significant deviations were observed between measured and calculated open-water coefficients, particularly under high propeller loads and extremely small distances between the blades of the forward and aft propellers.

Since TWIN-CRP systems are still relatively new to the market, data collection and the associated insights into the behavior of TWIN-CRP systems under both design and off-design conditions are crucial. This will help evaluate the advantages and disadvantages of TWIN-CRP compared to a single propeller in ship operation. Initial studies on the behavior of a ship equipped with TWIN-CRP systems and independently controllable propellers during acceleration, braking, and stopping will lay the groundwork for further research.

With the concentric shafts, the shaft bearings represent one of the biggest mechanical challenges in TWIN-CRP systems. Particularly during maneuvering, significant forces may act on the bearings. Therefore, in the first step, the transverse forces (bearing forces) of the entire system under selected operating conditions will be determined through both model testing and numerical analysis.

Title:	BREWEL – Simulation of Ships with Breaking Waves
Term:	2023 – 2026
Project manager:	Lars Lübke
Funding:	Federal Ministry for Economic Affairs and Climate Action
Project administration:	EuroNorm GmbH
Reg.-No.:	49MF230052

The final performance forecast is made after the contract is signed, based on measurements. If the forecast uncertainty of the numerical methods exceeds the considered power reserves, costly measures or penalty clauses are hard to avoid. Therefore, a high level of forecast accuracy is crucial for competitiveness and must be guaranteed to the highest possible extent. For ships with breaking waves, larger discrepancies occur between the calculation results and the measured resistance values. The calculated power values can deviate from the measured values by up to 20%. These values are far outside the usual safety margins and expected ranges. Simulations conducted on other facilities have shown similar deviations. The calculations were performed using different RANSE solvers (Reynolds-averaged Navier-Stokes Equations) and company-specific settings, so a general error in the calculation methods can be assumed. Further investigations have shown that, for example, the trim position can be ruled out as a source of error. The cause of the error is considered to be the wave system with the breaking bow wave. It is assumed that the breaking bow wave is not correctly captured in the simulations, and as a result, the wave interferences between the bow and stern wave systems are also affected. As part of the research topic, the prognosis accuracy for ships with breaking waves is to be improved and integrated into the procedural guidelines of SVA Potsdam. To achieve this, resistance, wave patterns, and wake fields for different ships will be measured and made available for the validation of simulations. The focus of the numerical simulations will be on the necessary grid resolution, the inclusion of surface tension in the simulations, and the identification of differences between homogeneous and heterogeneous multiphase models. The calculations will be conducted using different RANSE solvers and meshing strategies.

Title:	ActiveRudder – Innovative Propulsion and Manoeuvering System
Term:	2023 – 2025
Project manager:	Rhena Klose
Funding:	Federal Ministry for Economic Affairs and Climate Action
Project administration:	EuroNorm GmbH
Reg.-No.:	49MF220139

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).

Title:	Impact of Skeg Alternatives on Resistance and Yaw Stability
Term:	2022 – 2025
Project Manager:	Erik Schomburg
Funding:	Federal Ministry for Economic Affairs and Climate Action
Project administration:	EuroNorm GmbH
Reg.-No.:	49MF220037

In this R&D topic, the aim is to demonstrate the impact of skeg alternatives, such as fixed fins and/or enlarged rudder areas, on resistance, power requirements, as well as rolling behavior and course stability. Power savings, particularly in alternative power supply systems such as batteries or fuel cells, lead to significant weight, space, and cost reductions due to the scalable nature of storage systems. Since the proposed alternatives are not expected to involve significantly higher construction effort but may result in cumulative weight and resistance effects, resistance-reducing measures are generally of great interest to shipyards and ship operators, especially in the context of rising fuel prices.

The project aims to develop replacement systems for skegs that provide the same yaw stability while reducing ship resistance. The development of these alternatives will be carried out using numerical flow simulations. Model tests will provide insights into power requirements, rolling behavior, and maneuvering characteristics with the replacement systems. The development will focus on two different types of twin-screw vessels, as these are considered to have the highest application potential. The fundamental assumption is that a fully submerged fin can generate greater lift for the same surface area compared to a hull-integrated skeg. This hypothesis will be tested within the scope of this research topic.