Research

Title:	Ships in marginal seas in off-design situations – SiRiOS
Term:	12/2021 – 05/2024
Project Manager:	Kay Domke
Founding:	Ministry for Economic Affairs and Energy
Project administration:	EuroNorm GmbH
Reg.-No.:	49MF210150

In this context, the recording of the resistance and propulsion characteristics as well as the rudder forces is to be extended from calm water conditions to the observation during manoeuvring and in waves. The scope of measurement data is to be increased, while at the same time reducing the size of the sea state model. In order to meet the requirements of these experiments, the influences of scale and Reynolds number must be taken into account which leads then to the limits of the test parameters.
Extensive experimental and numerical investigations are being carried out on a large-scale model (typical model scale for resistance and propulsion tests) and a seakeeping model to test the scaling laws and for validation. Especially for seakeeping tests it has to be investigated how the maximisation of the scale and the measurement value acquisition influence each other in order to be able to further provide a realistic performance estimation and to investigate the ship behaviour in waves. The spectrum of manoeuvring and seakeeping tests will be mapped as completely as possible with a simple simulation tool (programme modules from “Uthlande”), too.
The integration of different measurement concepts of the various types of tests into one model requires the establishment of contemporary design procedures with CAD assemblies and optimisation of the individual components with FEM.
For efficient test preparation (installation/removal and conversion), the standardisation of a test set-up has to be optimised, among other things by using special mechanical installations such as trim beams. To support this, a ‘motion compensation platform’ is modified into an inertial balance, which is used to check and determine the ship’s centre of gravity already in the non-floating preparation process, in order to prepare the trimming of the metacentric height more efficiently and thus to make the trimming process more time effective.
An important goal is to establish an experimental technology for measuring extensive data throughout the measurement run.
As a result, guidelines shall be developed which clarify the smallest possible model size at which still allows a huge spectrum of measured commponents. The possibility of providing additional measurement variables in standard experiments must be validated and communicated.

Title:	Ships in marginal seas in off-design situations – SiRiOS
Term:	11/2021 – 04/2024
Project Manager:	Martin Börner
Founding:	Ministry for Economic Affairs and Energy
Project administration:	EuroNorm GmbH
Reg.-No.:	49VF210028

One variant envisages the use of autonomously acting “tractors” in a network, which act under coupling of the respective control and using logical algorithms for decision-making. Another envisaged variant looks at the self-retracting ship by means of mooring devices permanently mounted on the ship.
The technical solution approach consists of identifying the system-based weak points of a towed system. The focus here is on determining the hydrodynamic and technical boundary conditions.
The aim is to develop initial indications of the expected forces and hydrodynamic system properties by means of targeted CFD calculations (scenarios that cannot be carried out in the model test). This includes, among other things, the driving behaviour and the towing performance, especially for curves, as well as the forces for driving in restricted fairways with different channel cross-sections and distances to the shore. The simulation results are to be validated and supplemented on the basis of model tests with a model in a true-to-scale canal replica, and solution approaches are to be developed by means of coordinated test series. Based on the results obtained in the R&D project A-Swarm (03SX485A), manoeuvring/drive units will be designed and dimensioned. Another focus is the investigation of a coupling system that fulfils corresponding criteria such as reliability, safety, redundancy, economic efficiency and practical suitability. Based on the results, principle solutions regarding occurring problems such as encounters, overtaking, junctions and the general occurrence of obstacles and imponderables will be discussed and outlined. A possible energy concept is to be developed with a focus on technical feasibility. In addition, an onboard energy concept is to be designed or existing solutions are to be integrated into the overall system in such a way that an au-tonomous, redundant system that is temporarily independent of shore power can be realised.
As a result, overall systems consisting of ship, shoreside infrastructure and towing system are to be outlined, which meet the requirements of an autonomous towing system and are as economical, climate neutral and safe as possible.

The aim of this sub-project is the design, construction and provision of two test vehicles, which are to be used for testing the test field environment on the one hand and as platforms for third-party projects on the other. The test vehicles are modular in design and can operate in a two-man system as well as be coupled together and decoupled again to form larger units. The test vehicles will create a development environment that can be used in a variety of ways to develop the sensor, control and drive technology required for autonomous operation. Particular attention is being paid here on the one hand to a drive with the lowest possible emissions, and on the other hand to a high degree of compatibility with other research projects in this field in order to achieve high synergy effects.
The test vehicles to be developed should, on the one hand, take up the modular concept of the known pushed train technology introduced in the region and be large enough to be able to demonstrate logistics chains, on the other hand, they should not exceed the size of small vehicles according to the Inland Navigation Inspection Regulations (L < 20 m) in order not to have to carry out lengthy European approval procedures. Two coupling units are planned, which together have a length of approx. 14.5 m and, when coupled with the vehicles from the A-SWARM project, are 19.5 m long.

Title:	Propeller design method for low cavitation numbers
Term:	01/2021 – 06/2023
Project Manager:	Simon Froitzheim
Founding:	Federal Ministry for Economic Affairs and Energy
Project administration:	EuroNorm GmbH
Reg.-No.:	49MF200132

It must be possible to integrate the profile family into the optimisation process of propeller design programmes (lifting surface procedure VORTEX, optimiser VTXopt). The focus is on avoiding leading edge layer cavitation. The profile investigations are to be carried out both on the basis of a calculation method to be selected for thick profiles (e.g. XFOIL) and on the basis of CFD calculations. Based on the calculations, the calculation method for thick profiles will be validated and optimised for implementation in VTXopt. In addition, the calculations will be validated by means of experimental investigations.
Besides the mere suitability of cup propellers for modern fast ships, special attention is paid to the influence of the number of blades, as well as the way of scaling into the large version. The need for a dedicated friction line/correction method for cup propellers needs to be assessed and if needed, has to be developed.

Title:	Design of efficient ship propellers with unconven-tional shapes SVA: Design of unconventional propellers
Term:	12/2020 – 06/23
Project Manager:	Katrin Hellwig-Rieck
Founding:	Federal Ministry for Economic Affairs and Energy
Project administration:	Project Management Jülich
Partners:	MMG, TUHH, Friendship Systems AG, HSVA, Uni Rostock, ISA Propulsion GmbH & Co. KG
Reg.-No.:	03SX516E

The aim of the sub-project EukonPro of SVA Potsdam is the development of design strategies for unconventional propellers. Based on the work of SVA with the software PanMare, a complete design will be developed and at the same time the methods of PanMare and the HYKOPS module will be further developed in cooperation with the TUHH.
Compared to previous unconventional designs, the module developed in HYKOPS provides SVA’s propeller designers with further degrees of freedom in the arrangement of the profiles in space. This enables new design strategies to be discovered and evaluated. SVA Potsdam supports the development work by performing model tests and numerical simulations. The evaluation of the efficiency of different unconventional propeller designs of the research partners is carried out on the model of a twin-screw ship. As expected, the conversion methods of the propeller characteristics from the model to the full-scale version developed for conventional propellers are not easily applicable to unconventional propellers. Therefore, numerical investigations of scale effects and laminar-turbulent transition are also carried out on unconventional propeller geometries. Numerical calculations are carried out to support the analysis of full-scale measurements of the velocity in front of and behind the propeller.
In this project various numerical methods for prediction are to be applied to unconventional propeller shapes and evaluated with regard to their efficiency and analysis accuracy in order to develop them further. In addition to the knowledge gained from the application of numerical methods, the experimental investigation of selected propeller geometries will ensure the validity of the numerical calculations. Due to the consideration of propeller geometries at the limits of the technical possibilities, allow the conclusion that designs with more common shapes can also be reproduced.

Title:	Quiet transverse thrusters – Reducing the sound emission of transverse thrusters with methods of active vibration reduction SVA: Hydroacoustically optimised transverse thruster propellers and noise prediction
Term:	12/2020 – 11/2023
Project Manager:	Rhena Klose
Founding:	Federal Ministry for Economic Affairs and Energy
Project administration:	Project Management Jülich
Partners:	Jastram GmbH & Co. KG, University of Rostock (chairs LEMOS and ITU), Promarin Propeller und Marinetechnik GmbH, Wölfel Engineering GmbH & Co. KG
Reg.-No.:	03SX530C

With its know-how in propeller design, SVA is striving to develop a propeller design with high efficiency and reduced cavitation expansion and thus low noise radiation. This concerns both the sound propagation into the hull itself and the sound radiation into the sea. The engineering tools for determining the operating parameters in the propeller design phase are to be validated. The suitability of the potential theory propeller design and optimisation methods (VORTEX, panMARE) for the calculation and optimisation of transverse thruster propellers is to be determined.This will enable systematic calculations regarding the influence of geometry changes of the transverse thruster propeller on the risk of cavitation. Supplementary CFD calculations support the final determination of the propeller geometry.
Various propeller designs are to be investigated in detail by means of model tests with regard to their characteristic values, cavitation risk and noise radiation, which arevalidated and quantified by CFD calculations. In order to be able to quantify the noise reduction, acoustic measurements in the cavitation tunnel with the transverse thruster system (propeller in the transverse channel) are necessary. Challenges are posed by the limited dimensions of the entire transverse thruster system with the transverse channel and the associated strong sound reflections. Intensive metrological investigations as well as boundary element calculations (BEM) are required to determine the source levels which are necessary for a comparison and transfer to the full-scale design.
With regard to future regulations in the form of sound level limits, a reliable scaling to the sound levels of the full-scale system must be guaranteed. To this end, the procedures for converting the model scale sound spectra to full-scale and for predicting the sound level spectra of the transverse thruster system in the far field of the manoeuvring ship must be further developed and validated. Full-scale measurements under laboratory conditions serve to derive conversion rules from the model to the full-scale sound level spectra.

Title:	Hydrodynamic prediction and evaluation of realistic loads on ESDs SVA: Development of a measurement and scaling procedure for realistic prediction of transient forces on energy saving devices
Term:	10/2019 – 09/2022
Project Manager:	Pascal Anschau
Founding:	Federal Ministry for Economic Affairs and Energy
Project administration:	Project Management Jülich
Partners:	IBMV, MMG, Uni Rostoc
Reg.-No.:	03SX493C

The laboratory investigations, which will be carried out with two methods, optoelectronic and electromechanical, aim to develop measurement methods for high-frequency measurements of the force and pressure fluctuations on ESDs caused by turbulence and to provide measurement data for the validation of the numerical simulation method to be developed. The optoelectronic method to be used is a high-speed PIV (Particle Image Velocimetry) method. This will be used to investigate the flow around the ship’s stern and in particular the inflow and outflow of the ESDs. The electromechanical investigations are aimed at the high-frequency recording of the transient force and pressure fluctuations at the ESDs and in the propeller bearing on the model. A new measurement system is to be developed for measuring the forces at a wake equalizing duct, which allows the temporally high-resolution registration of all three force components and the pressure at the ESD; in addition, the radial propeller bearing forces will be recorded. The data generated in this way will provide insight into the pressure and force effects of the turbulent flow fluctuations.
Numerical simulations are carried out to determine the transferability of the model test results to the full-scale ship. The simulations will be validated with the corresponding measurement results. These investigations will initially lead to a procedure concept with which the force and pressure fluctuations at the duct can be transferred from model scale to the duct in the full-scale version. For the development of the scaling procedure, investigations will be carried out on different scales. A hybrid method to be developed is to be used for the simulations. From the simulations with different scales, it should be possible to make a statement about the size of the load peaks to be expected at the duct in the full-scale version, possibly also a statement about the probabilities of occurrence.

Title:	Influence of the deviation moments on the sea state behaviour
Term:	10/2019 – 03/22
Project Manager:	Dr. Matthias Fröhlich
Founding:	Federal Ministry for Economic Affairs and Energy
Project administration:	EuroNorm GmbH
Reg.-No.:	49MF190066

In order to be able to give an initial assessment of the influence of the deviation moments on the motion behaviour of ships, simulations will first be carried out using a linear strip method. The main focus here will be on how the interaction of the deviation moment with the corresponding main moments of inertia takes place and in which orders of magnitude this has an effect on the movement behaviour.
The second focus is the development of a control algorithm that allows a standard model to travel on a defined course at a given speed in waves without coupling the model to the towing vehicle in front. The challenge in the further development of this control algorithm is to take into account the motions induced by the waves in all 6 degrees of freedom when driving in waves. In particular, the rolling, pitching and diving motions of the ship have a decisive influence on the flow of the rudder. Especially when sailing in oblique waves, effects such as the immersion of the propeller and additional lateral forces due to the effect of the waves on the ship’s hull and a temporary loss of stability due to fluctuating lever arms have an influence on the course keeping ability. Such effects must be analysed in detail and their impact minimised by short reaction times of the controller.
As a result of the R&D project, reliable results will be available under which conditions and in which areas the deviation moments have a decisive influence on the movement behaviour of a ship and must be taken into account in the future.

Title:	Automatic Navigation Assistance System for Plan-ing and Semi-planing Crafts SVA: Evaluation of thrust measurements on planing boats
Term:	10/2019 – 09/2022
Project Manager:	T. Nietzschmann (Kay Domke)
Founding:	Federal Ministry for Economic Affairs and Energy
Project administration:	Project Management Jülich
Partners:	Friendship, TU Berlin, Shipyard UZMAR (Kocaeli)
Reg.-No.:	03SX523B

The goal is pursued in a holistic approach:
A. Model tests and numerical calculations to understand the unstable behaviour and its causes.
B. Shape optimization strategies aimed at minimising the probability of unstable behaviour occurring.
C. Especially from A), possibilities and methods are derived to be able to make predictions about the unstable behavior in real operation, and to avoid it by changes to the driving regime
In addition to extensive model tests with novel measurement tasks, numerical calculations are used to gain knowledge and adapt optimisation strategies. The model tests and calculations are validated on the basis of full-scale measurements. The key point here is the novelty of thrust measurements on the ship’s propeller in the full-scale trials and the prognostic intervention in the driving regime, based on measurements of the operating conditions.
The objectives of the subproject of SVA Potsdam are:
• Development, design and construction of rudder force balances for small models.
• Integration of a model test setup for propulsion tests with free rolling motions.
• Design of a propeller geometry for the planning boatand manufacturing of the ship models and the propeller models.
• Development and provision of a measuring system to record the instationary pressure distribution on the ship hull of the model and the full-scale model. Especially for the optimization of the data analysis the test setup shall be as flexible as possible and buildt up as a mobile test setup.
• Development, design, manufacturing and commissioning of a measuring element for the registration of propeller thrust and torque in the full-scale version. This construction has to be adapted to the conditions in the prototype.
• Cavitation observations in ship operation in correlation to thrust measurement.
• Merging of the measurement data on propulsors, motion behaviour and pressure.

Title:	A SWARM Autonomous electric shipping on waterways in metropolitan region
Term:	09/2019 – 08/2022
Project Manager:	Dr. C. Masilge
Founding:	Federal Ministry for Economic Affairs and Energy
Project administration:	Project Management Jülich
Partners:	BEHALA, Infineon, Veinland, TU Berlin, Uni Rostock
Reg.-No.:	03SX485A

Both the technological requirements for the watercraft itself are considered, but also whether and which technological requirements for the infrastructure in terms of communication and positioning are needed. The processes of going alongside a pier as well as loading and unloading are of secondary importance in this first step; the project will first address the question of autonomous movement on the water. In particular, the question of whether it is possible to equip the vehicle itself with sufficient sensor technology so that it can navigate safely without further land-based aids, apart from satellite positioning, or whether it is necessary to install additional infrastructure on the waterway for safe autonomous operation is to be addressed. The vessels will be equipped with state-of-the-art sensors that enables a sufficiently accurate description of the environment. It has to be investigated whether it is mandatory to use an external traffic control or is it possible to enable the vessels to make its own decisions by an AI system on board. Another aspect is the optimization of the technology with regard to the target parameters of the most precise positioning possible and the least possible use of energy, in order to jeopardize neither traffic safety nor marketability in the long term. The result of the project will be a technology that enables the autonomous and decarbonized operation of smaller watercraft on inland waterways in the vicinity of metropolitan areas. The technical feasibility will be demonstrated by two test vehicles, which will be used during the project to test the combination of the technologies used. The operational aspects will be illustrated in the form of utilisation concepts and demonstrated on the basis of a specific use case to be selected in the course of the project. In order to enable the shift of freight transports from road to waterways in metropolitan regions in the future, an autonomous electrically driven water vehicle will be developed, which is able to reach the metropolis energetically favourable coupled with similar containers and which splits up in the sense of the (pre-)last mile and reaches the destination autonomously.
The demonstrators will initially be developed and tested under laboratory conditions in the towing tank for testing the developed technologies individually, as well as in interaction and as a whole. Ultimately, the functionality of the autonomous electric watercraft system is to be demonstrated by means of an outdoor test in a real laboratory on inner-Berlin waterways.

Title:	Prediction of sound level spectra of ships based on hybrid measurement
Term:	09/2019 – 02/2022
Project Manager:	Kay Domke
Founding:	Federal Ministry for Economic Affairs and Energy
Project administration:	EuroNorm GmbH
Reg.-No.:	49VF190016

On the basis of hybrid measurements, a concept of sound pressure level analysis is to be developed with which the measurement results of the sound measurements of the towing tank and cavitation tunnel can be combined and compiled into a meaningful overall result. It is particularly important to take into account the special characteristics of the respective test facility. The development of the hybrid sound pressure level prediction includes the extension of the measurement procedures in the towing tank to minimise the background noise for the passing ship model and the extension of the measurements in the cavitation tunnel into the range of Froud’s similarity to generate comparable spectra. For the cavitation-free operating points of the ship (propeller), accurate predictions of the radiated sound level spectra can already be worked out from the measurements in the towing tank. If cavitation occurs, the noise level measurements in the cavitation tunnel are decisive for the prognosis. By comparing the measurements in both test facilities, the accuracy of the transfer of the sound levels measured in the cavitation tunnel to free-field conditions can be tested. Since often only one propeller of twin- and multi-screw ships is measured in the cavitation tunnel, the necessary corrections to take into account the influence of several propellers on the sound spectra can be derived from the towing tank measurements and procedures can be checked.
The experimental investigations are to be accompanied by theoretical work. The aim is to obtain knowledge about simulation results on sound propagation in the towing tank, taking into account wall and bottom reflections, as well as the inclusion of the beach. Boundary element methods can provide information on a favourable positioning of the sound sensors. CFD calculations for the cavitation tunnel measurement section will also be carried out. This will consolidate the knowledge of sound propagation in this specific test facility and will contribute to the evaluation of the sound level spectra measured later.
For the conversion of measurements on the model scale to full-scale executions, recommendations are to be worked out on how a conversion to twin-screw vessels can be carried out. It is important to note that the two-pole theory must be taken into account for propulsion systems in which the propeller blades do not have a fixed phase relation to each other

Title:	Investigation of the influence of pre-swirl ducts/pre-swirl nozzles on the manoeuvring char-acteristics of complete ships – PSDMan SVA: Manoeuvring behaviour of complete ships with pre-swirl nozzle
Term:	07/2019 – 06/2022
Project Manager:	Lars Lübke
Founding:	Federal Ministry for Economic Affairs and Energy
Project administration:	Project Management Jülich
Partners:	IBMV, BMS, TUHH
Reg.-No.:	03SX488C

The manoeuvring characteristics of the model are determined by tests with and without a balancing nozzle. The focus here is on the yaw stability. Field tests are necessary to carry out turning circle tests. The nozzle forces are measured during the manoeuvres in order to be able to determine load peaks.
The measurements will be supplemented or extended by extensive numerical simulations, whereby the experimental results will be used to validate the simulation results. An efficient setup for performing manoeuvre simulations will be developed. The forces on the ship are to be calculated for different manoeuvres. Both captive tests (guided ship/model) and free manoeuvre simulations will be carried out. The use of overlapping grids is crucial for carrying out the numerical simulations, which should enable, for example, rudder control simulations to be carried out more easily. Different turbulence models are used, ranging from a fully turbulent flow with a two-equation model to hybrid methods. The simulations are carried out in the scale of the model as well as of the ship, which allows an estimation of the Reynolds number effects. The course stability is to be quantified with the stability index, among other things. The scope of the simulation includes “pure yaw” and “pure sway”. This enables the determination of the manoeuvring characteristics on the basis of a restricted set of coefficients. Furthermore, manoeuvres such as a turning circle simulation are to be simulated directly.
Another goal is to carry out a coordinated design of the PSD and propeller under consideration to the manoeuvring behaviour, taking into account the mutual interactions. The power reduction shall be quantified experimentally.
As a result of the project, the influence of the PSDs on the manoeuvring behaviour will be quantified and the forces on the PSD during manoeuvring will be determined.