Dr. Dr. h.c. Gun­ter Gerbeth

Director Institute of Fluid Dynamics
Phone: +49 351 260 3480
+49 351 260 3484

Dr. Gerd Mutschke
Phone: +49 351 260 2480

Get more information

General description of the Alliance

1 Framework Concept

1.1 Future challenges for research in the chosen field

The growing energy demand of mankind, in connection with the global risks of climate change due to emissions of greenhouse gases, requires a rapid substitution of fossil combustibles by renewable energy sources. The widespread deployment of solar and wind power in the future will face the fundamental problem of intermittency which requires demand flexibility, backup power sources, and energy storage capacities for days or weeks. Significant improvements of the energy profit ratio of photovoltaics will be of further help to make Germany’s energy turnaround a success. Closely related to that, there is an urgent need to enhance the efficiency of major energy consumers, in particular in metallurgy and chemistry. On the nuclear side, efforts will be needed to reduce the amount of long-lived radioactive wastes by treating them in transmutation systems.
Basic and applied research on Liquid Metal Technologies represents a surprising bandwidth ranging from high-temperature energy conversion, new kinds of liquid metal batteries, the production of solar-grade silicon, carbon dioxide free production of hydrogen, liquid metal targets in modern neutron sources and transmutation systems, casting of steel and light metals, welding and soldering processes, to basic laboratory experiments with relevance to liquid metal cooled systems, materials processing as well as to geo- and astrophysics.
The efficiency of energy conversion processes can, in general, be increased by using higher temperature levels. Today the heat carriers in, e.g., concentrated solar power systems are molten salts or thermal oils, which are limited in their maximum temperatures and the related material compatibilities. There is no doubt that the use of liquid metals for that purpose would allow to increase the efficiency significantly. Of course, the liquid metal system must be safe and under reliable control. Highest energy conversion rates can be obtained by using processes with phase changes, hence one project will deal with alkali metal thermo-electric converters. Another project will study liquid metal batteries, a completely new idea for base-load energy storage. A new idea of a carbon dioxide free production of hydrogen by means of a liquid metal bubble column reactor will be in the focus of a further project. Thus, most of the Alliance research activities clearly belong to the recent new requirements for innovative energy conversion and energy storage systems.
Most of the metallurgical and crystal growth processes comprise phases with liquid metals (or liquid semiconductors with very similar properties). As the production and processing of metals and semiconductors are characterized by high energy consumption, a part of the Alliance activities will address the increase of energy and resource efficiency in metal casting and photovoltaic silicon production. A related issue is the development of a casting route for new high-temperature steels with nanodispersed particles. These steels will, in turn, find applications in the above mentioned high-temperature energy conversion systems.
For the instrumentation and on-line monitoring of liquid metal systems the past decade represented a break-through as many measuring systems have been developed and are today ready for a regular use. Indeed, these new kinds of instrumentation, which are available now or just at the edge of being in broad use, represent the leading pre-condition for almost the complete research program proposed here in frame of the Helmholtz Alliance.
Measurements are an unavoidable basis for any experimental research on liquid metal technologies. The most desirable next step is always to influence or control the melt flow. As many such melts are chemically aggressive and at high temperatures, e.g. molten steel and molten silicon at about 1500°C, it is highly attractive to look for a contactless influence on those melts. This is possible by magnetic fields. Applying steady or alternating magnetic fields offers broad possibilities for any desirable modification of liquid metal flows. This field is known as Magnetohydrodynamics (MHD) or, with stronger reference to applications, as Electromagnetic Processing of Materials (EPM).
There are many basic problems connected with this interaction between flows and magnetic fields such as: How is turbulence modified by a magnetic field? Can laboratory experiments contribute to the solution of long-standing problems in geo- and astrophysical MHD? What is the origin of the Earth magnetic field? Is a fully contactless monitoring of flow fields possible as it is done in medicine by the measurement of electric current distributions (Magneto-encephalography)? Thus, the long-term scientific goals of the Alliance are:
  • development of new solutions for the use of liquid metals in solar power energy conversion and storage,
  • development of new liquid metal batteries,
  • development of a technology for the carbon dioxide free production of hydrogen using a liquid metal bubble column reactor,
  • development of magnetic flow control for improved photovoltaic silicon processing in the established directional solidification as well as in a completely new process avoiding sawing losses,
  • development of tailored magnetic field control for the continuous casting of steel and for a completely new casting route of ODS steel production,
  • experimental insight into basic MHD instabilities, like self-excitation etc., with rele-vance to large liquid-metal cooled systems, liquid metal batteries as well as to geo- and astrophysics,
  • further development of liquid metal measurement systems as the key basis for all experiments, as well as for a safe and reliable operation of liquid metal systems,
  • further development of validated numerical tools for the prediction of those flows and related heat & mass transports.
In order to define the scope of the proposed Alliance, it is also useful to mention neighboring research fields which the Alliance will not address. LIMTECH will not deal with problems of ferrofluids or the application of high magnetic fields. Though the latter is an important field of basic research, most of the applications with magnetic flow control are focused on tailored fields of preferably low strengths for the simple reason of the related costs of the magnetic system. The Alliance will only partly address material problems of corrosion and long-term sustainability since a dedicated consideration of those aspects would require efforts beyond the possibilities of the Alliance. In addition, material aspects are already investigated in frame of running Helmholtz programs. LIMTECH will concentrate its activities on the melt flows and the related heat & mass transports, either in single- or two-phase flows of liquid metals or semiconductor melts.

1.2 The Helmholtz Alliance as a network of complementary excellence

The proposed Helmholtz Alliance LIMTECH shall bundle the R&D activities on Liquid Metal Technologies as they had grown over the past decade both at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and at Karlsruhe Institute of Technology (KIT) and reached already a worldwide leading position. In the same time, related activities at universities experienced a strong development, in particular at Technical University Dresden (TUD), TU Bergakademie Freiberg (TUBAF), Technical University Ilmenau (TUI) and Leibniz University Hannover (LUH). The basic idea with the Helmholtz Alliance LIMTECH consists in a joint research programme among those partners, addressing break-through technological goals by bringing together for the first time all relevant Helmholtz and university institutions. In this way, the partly existing worldwide leading role of the German community in this field shall be continuously strengthened.
LIMTECH will provide an essential basis for a strong positioning of the Helmholtz Association in the innovative field of liquid metal technologies. Till now, the activities at KIT where mainly focused on liquid metal targets, aspects of nuclear safety for sodium or lead-bismuth cooled systems, fusion related liquid metal flows, and the realization of a pioneering dynamo experiment. All these activities were part of related Helmholtz programmes, mainly Nuclear Safety. HZDR has great experience in basic problems such as dynamo experiments or the modeling of astrophysical flow phenomena, in applied research on metal casting and crystal growth, and particularly in the development of related measurement techniques. HZDR is heavily involved into the Collaborative Research Centre SFB 609 at TUD “Electromagnetic flow control in metallurgy, crystal growth, and electrochemistry” which is funded by DFG since 2002. It already combines the activities of HZDR, TUD and TUBAF. In 2008 the German Wissenschaftsrat evaluated HZDR and recommended for the liquid metal activities that “…the in Dresden de facto existing center of excellence in this field is worldwide leading and should be consequently further developed”. Outstanding large-scale liquid metal facilities exist or received approval recently at HZDR (DRESDYN, 23 M€) and at KIT (KALLA/KASOLA, 15 M€). They will further improve the experimental possibilities at both institutions significantly.
HZDR became a member of Helmholtz Association at the beginning of 2011. LIMTECH will represent for the Helmholtz Association a strategic added value by intensifying and bringing together research activities in a new innovative and highly interdisciplinary field.
LIMTECH is mainly based on the capacities grown over appr. the past 15 years at HZDR and KIT in the fields of liquid metal systems, their measurement and magnetic control. As typical for Helmholtz centers, mid- and large-scale facilities have particularly been installed in both institutions. Thus, a long-term experience exists on both sides with the operation, safety and instrumentation of liquid metal loop- and pool-type experiments. LIMTECH is essentially based on those experimental capabilities. Further Helmholtz participants will be Forschungszentrum Jülich (FZJ) and the German Aerospace Center (DLR).
On the other hand, powerful university teams in these fields exist, in particular at TUD, TUBAF, TUI and LUH. Further partners involved in LIMTECH will be the Georg-August-University Göttingen (UG), RWTH Aachen (RWTH) and University of Potsdam (UP). Foreign partners of the Alliance will be the Institute of Physics of the University of Latvia (IPUL) and the Coventry University (CU). These foreign partners bring in specific world-leading capacities as well as unique experimental possibilities in case of IPUL. Therefore, they should be involved as full project partners. In addition, there will be a long list of associated partners without financial involvement into the Alliance.

1.3 The Helmholtz Alliance as an element for further structural development

1.3.1 Long-term scientific and structural objectives, continuation and further development beyond the funding period

Most of the Alliance activities belong to the research field Energy of the Helmholtz Association, in particular the programmes of Renewable Energies and Efficient Energy Conversion. Within the research field Energy LIMTECH will also involve contributions to the programs Nuclear Safety Research and Nuclear Fusion as these programs involve also liquid metal cooling problems of next-generation nuclear reactors as well as liquid metal solutions for the blanket or diverter cooling, respectively. With respect to the recently discussed and prepared new structure of the research field Energy, LIMTECH will in future contribute to the Topics of Concentrating Solar Power (CSP), electrochemical storages, energy efficient processes, mineral resources, besides the continuing programmes of nuclear safety and fusion. In close cooperation with DLR, the use of liquid metal systems for receiver or storage applications in CSP shall be investigated and pushed forward in the near future. Hence, LIMTECH will be active in almost all programmes of the research field Energy.
In addition, LIMTECH will also comprise attractive links to the Research Fields Earth and Environment (programme: the Changing Earth) and Key Technologies (programme: Advanced Engineering Materials). For the geo- and astrophysical activities a powerful network exists already in Germany by means of the DFG Priority Programme 1488 “Planetary Magnetism”, in which the related liquid metal experiments at HZDR are involved. Eventually, the activities in the Research Field Structure of Materials on the development of liquid metal targets for new high-intensity spallation sources at large-scale projects such as FAIR, ESS, IFMIF will strongly benefit from the Alliance works.
As the research on Liquid Metal Technologies and MHD has many specific directions and applications, it is the intention of HZDR and KIT to suggest these activities within the next PoF-3 as a so-called “Querschnittsverbund”, a structural form which was recently suggested for implementation by the German Ministry BMBF.
LIMTECH bundles the already existing unique liquid metal infrastructures and competencies within the Helmholtz association in both a basic science as well as an application oriented manner. In that sense LIMTECH can be conceived as a first step towards a future liquid metal Helmholtz research platform. Another significant added value of LIMTECH arises from the interdisciplinary interaction between the partners involved and the efficient integration of external partners from science and industry. LIMTECH represents a research project of cross-cutting nature not only in the Helmholtz energy research mission but also in the fields of Earth and Environment, Structure of Matter and Key Technologies. The organisation of LIMTECH with its PhD program is particularly aiming to attract young scientists. LIMTECH will result in a clear added value for universities, as students can be trained and researchers get access to large-scale Helmholtz facilities. In turn, the Helmholtz Association will strongly benefit from the involvement of students and university researchers.
In frame of the Helmholtz research field Energy, the liquid metal activities for solar power conversion, enhanced energy and resource efficiency, improved technologies for photovoltaic silicon production, high-temperature thermodynamic processes, and carbon dioxide free hydrogen production will be grouped into the corresponding new programmes which are just in discussion and preparation. There is the clear intention of the Helmholtz members of the Alliance to include at least a part of those topics into the next PoF-3. It would become effective at the beginning of 2015, which is just in the middle of the proposed Alliance period. This fits ideally into the intended strategy to transfer the liquid metal technologies more and more into the basic Helmholtz programmes.

1.3.2 Compatibility with the structural and development plans of the Centres involved

HZDR is a new member of HGF since the beginning of 2011. At both KIT and HZDR a part of the liquid metal activities was up to now performed in frame of the Helmholtz programme Nuclear Safety. This will be continued in agreement with the recent “Energieforschungs-programm der Bundesregierung” and, in particular, considering the involvement of both teams into international projects. On the other hand, transform of those capabilities to recent requirements for new energy conversion and storage technologies is foreseen both at HZDR and KIT. LIMTECH exactly points into this direction. This transform is accompanied by structural transform activities. At HZDR it the two basically nuclear oriented institutes of “Safety Research” and “Radiochemistry” were closed at the end of 2011, and the new institutes of “Fluiddynamics” and “Resource Ecology” were created with the begin of 2012. The tendency to new energy topics is clearly visible in this structural transform. The Alliance LIMTECH would ideally fit into this transform process and the strengthening of the fluiddynamic activities at HZDR.
At HZDR, the large-scale project DRESDYN (DRESden Sodium facility for DYNamo and thermohydraulic studies) is in operation since about two years. It will provide a new liquid metal laboratory with many flexible possibilities for MHD experiments. The approved budget is about 23 M€. The construction of the new building shall start in autumn 2012, first experiments can be expected to be performed at the end of 2014.
The new Helmholtz Institute Freiberg (HIF) for Resource Technology was founded in 2011 together by TUBAF and HZDR. It will perform research and developments in the field of metal resource technologies, which is of future strategic importance. The project A5 of the Alliance will address problems of magnetic particle separation in close cooperation with TUBAF and HIF.
At KIT, particularly the topics related to concentrating solar power and hydrogen production will be part of new programme contributions in the renewable energy and energy efficiency area, which are currently being shaped. The Alliance activities of KIT are all planned with a strong link between institutes of the former Research Center and the University of Karlsruhe. This utilizes the new scientific opportunities of KIT and contributes at the same time to further strengthening the newly established scientific links. The KIT liquid metal laboratories KALLA and KASOLA have been awarded substantial investments of appr. 3.5 M€ in recent years, which complement the already existing facilities of appr. 11.5 M€.