Practical trainings, student assistants and theses

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Energy efficiency analysis of side chain oxidation of aromatics hydrocarbons

Bachelor theses / Master theses / Diploma theses

The chemical industry uses 5% of all the energy consumed in Germany. Small changes in selected processes can thus lead to important energy savings and reduce the overall environmental footprint of the country.
The oxidation of the side chain of aromatic hydrocarbon is an important stage in the production of commodities like PET, phenol, or styrene, among many other chemicals.
The purpose of the thesis is to evaluate the energy used in the production of chemicals where side chain oxidation is a necessary stage. In addition, energy losses and potential energy savings need to be identified.
Tasks:
• Assess the energy use of the production of PET, phenol, and styrene.
• Evaluate the energy importance of side chain oxidation within these processes,
• Propose energy-saving measures
• Assess additional processes with side chain oxidation

Department: Experimental Thermal Fluid Dynamics

Requirements

• Student of Chemical, Process Engineering, or similar.
• High level of English.

Conditions

• 4-6 Months
• Starting as soon as possible

Online application

Please apply online: english / german

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Untersuchung zur Hydrodynamik in Blasensäulen

Master theses / Diploma theses / compulsory internship

Blasensäulen sind aufgrund ihrer einfachen Bauweise ein beliebter Reaktortyp in der chemischen Industrie. Die genaue Auslegung und der optimierte Betrieb in Bezug auf hohen Umsatz und Ausbeute erfordert ein detailliertes Verständnis der in Blasensäulenreaktoren ablaufenden Prozesse. Hierbei spielen vor allem lokale Hydrodynamische Effekte und ihr Einfluss auf den Stofftransport eine wesentliche Rolle. An einem bestehenden Versuchsaufbau sind experimentelle Studien zur Hydrodynamik durchzuführen und lokale Daten wie Phasengeschwindigkeiten und charakteristische Parameter der Blasen für verschiedene Versuchsbedingungen zu extrahieren.

Department: Experimental Thermal Fluid Dynamics

Contact: Kipping, Ragna

Requirements

- Studium der Verfahrenstechnik, Chemie-Ingenieurwesen oder vergleichbar
- Freude am experimentellen Arbeiten
- Kenntnisse in MATLAB für die Datenauswertung wünschenswert

Conditions

Beginn: ab sofort

Online application

Please apply online: english / german

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Experimental measurement on the bubble generation by flexible membrane diffusers

Student practical training / Bachelor theses / Master theses / Diploma theses

Foto: Dynamic Bubbling Regime ©Copyright: Ehsan MohseniIn Germany, wastewater is treated in 10000 plants, which use 4,400 GWh of energy per year. From this big figure, only the aeration process in activated sludge basins consumes up to 50%. Aerators with flexible membranes are currently state of the art. However, the aeration process suffers from some limitations such as large bubble size, high-pressure drop of the diffusers, and inadequate mixing. Initial bubble size in gas dispersion is of great importance since it determines the ascent and coalescence rate, macro mixing by turbulence, and oxygen transfer from the bubble to the fluid phase. Although the initial bubble size generated by membrane diffusers is reported in few publications, there is a lack of information on the actual bubble size distribution produced by this type of aerators. To investigate on this issue, high precision optical measurement techniques, such as fluidic sensor microscope or videometery are known to be versatile approaches. Hence, the description of the offered task is as follow:
- Acquiring knowledge in the following areas: activated sludge process, optical measurement techniques, mass transfer in two phase flows
- Preparation of the experimental setup
- Conducting the experiment using high-resolution optical measurement techniques.
- Post processing and evaluating the data
- Writing and presenting the results

Department: Experimental Thermal Fluid Dynamics

Contact: Mohseni, Ehsan

Requirements

• Study programs in the fields of process engineering, chemical engineering, mechanical engineering and related degree programs
• Knowledge in the following areas is advantageous: oxygen mass transfer, biological wastewater treatment, optical measurement techniques.
• Enthusiasm for experimental work
• Data analysis in Matlab
• Structured and independent working

Conditions

The candidate can start from September 2017. The duration of the project can be up to 6 months.

Online application

Please apply online: english / german

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Untersuchung der Fluiddynamik von Zweiphasenströmungen in Kolonnen mit Anstaupackungen

Bachelor theses / Master theses / Diploma theses / compulsory internship

In thermischen Trennapparaten, z.B. Rektifikations- oder Absorptionskolonnen, hat die Fluiddynamik der beteiligten Phasen einen entscheidenden Einfluss auf die Effizienz der Stofftrennung. Eine Möglichkeit, den Kontakt zwischen Gas- und Flüssigkeitsphase zu intensivieren und damit den Stoffübergang zu verbessern, bieten Anstaupackungen. Sie bestehen aus Packungslagen zweier geometrischer Oberflächen, welche abwechselnd axial angeordnet werden. Durch die Kombination unterschiedlicher Packungen entstehen verschiedene Strömungsmuster (Blasenströmung, Sprudelschicht, Filmströmung), welche mittels der ultraschnellen Röntgentomografie am HZDR zeitlich und örtlich hochaufgelöst erfasst werden können.

Aus den tomografischen Bilddaten sollen im Rahmen einer studentischen Arbeit wichtige fluiddynamische Parameter wie die Phasengrenzfläche extrahiert werden. Dazu sind geeignete Algorithmen zu entwickeln und in MATLAB® zu implementieren.

Department: Experimental Thermal Fluid Dynamics

Contact: Sohr, Johanna, Dr. Bieberle, Martina

Requirements

• mathematisch-naturwissenschaftliches oder ingenieurwissenschaftliches Studium
• Programmierkenntnisse in MATLAB® und Vorkenntnisse in der Bilddatenverarbeitung sind hilfreich

Conditions

Beginn: ab sofort
Bearbeitungszeit: 4-6 Monate

Links:

Online application

Please apply online: english / german

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Modellierung und Simulation eines tubularen Hochtemperaturelektrolyseurs zur Wasserstoffproduktion

Bachelor theses / Master theses / Diploma theses

Das Institut für Fluiddynamik des Helmholtz-Zentrums Dresden-Rossendorf (HZDR) beschäftigt sich unter anderem mit Fragen der Modellbildung und Simulation von Stoff- und Wärmetransportvorgängen in verfahrenstechnischen Apparaten.

Im Rahmen eines Forschungsprojektes zur Entwicklung eines tubularen Hochtemperatur-Dampfelektrolyseurs mit integrierter Kohlenwasserstoffsynthese soll mit Hilfe kommerzieller Softwarelösungen (COMSOL, MATLAB, usw.) das stationäre und dynamische Betriebsverhalten einer SOEC (Solid Oxide Electrolyzer Cell) charakterisiert werden. Dabei sind die Einflüsse verschiedener Parameter, wie z.B. der Zellgeometrie, Materialeigenschaften, Betriebstemperatur und Gasdurchsatzraten auf das Betriebsverhalten der Zelle zu untersuchen. Auf Basis dieser Simulationen soll ein Konzept zur Prozesssteuerung und -instrumentierung entwickelt werden.

Mögliche Aufgaben:

• Erstellung des zweidimensionalen Geometriemodells eines tubularen Dampfelektrolyseurs mit Hilfe der Software COMSOL Multiphysics
• Modellierung und stationäre Simulation des Stoff- und Wärmetransportes innerhalb des Elektrolyseurs
• Erstellung eines dynamischen Modells eines kombinierten Elektrolyse-Syntheseapparates mit Hilfe der Software MATLAB Simulink
• Durchführung einer Sensitivitätsanalyse hinsichtlich der grundlegenden Betriebsparameter des Elektrolyseurs
• Auswahl geeigneter Analysetechnik zur Prozesscharakterisierung und Identifizierung relevanter Messstellen auf Basis der durchgeführten Simulationen

Department: Experimental Thermal Fluid Dynamics

Contact: Fogel, Stefan

Requirements

• Student(in) der Studiengänge Chemieingenieurwesen, Verfahrenstechnik, Energietechnik, Maschinenbau o. ähnlicher Ausrichtung
• Sorgfältige und selbstständige Arbeitsweise
• Freude an der wissenschaftlichen Arbeit
• Erste Erfahrungen mit den Programmen MATLAB und COMSOL Multiphysics von Vorteil

Conditions

Beginn: ab sofort
Bearbeitungszeit: 4-6 Monate

Online application

Please apply online: english / german

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Phasengrenzflächenextraktion aus Datensätzen der ultraschnellen Röntgen-Computertomographie

Master theses / Diploma theses

Foto: ROFEX CAD ©Copyright: Dr. Frank BarthelAm Helmholtz-Zentrum Dresden-Rossendorf wurde ein ultraschnelles Röntgen-Computertomographie-System (ROFEX) entwickelt, mit dessen Hilfe dynamische Prozesse mit Bildraten von bis zu 8000 s-1 abgebildet werden können. In erster Linie werden damit Untersuchungen an mehrphasigen Strömungen durchgeführt. Ein wichtiger Parameter zu deren Charakterisierung ist die Phasengrenzflächendichte. Aktuell wird diese in einem zweistufigen Prozess bestimmt: zunächst werden die Phasen segmentiert und anschließend wird aus den binären Daten die Oberfläche extrahiert. Alternativ dazu sollen in dieser Arbeit Methoden entwickelt bzw. untersucht werden, welche die Phasengrenzfläche direkt aus den ursprünglich rekonstruierten Bildern bestimmen.

Folgende Teilaufgaben sind zu bearbeiten:
• Literaturrecherche zu vorhandenen Methoden
• Implementierung ausgewählter Algorithmen
• Bewertung der Genauigkeit anhand simulierter und realer CT-Daten

Department: Experimental Thermal Fluid Dynamics

Contact: Dr. Bieberle, Martina, Wagner, Michael

Requirements

• Studium der Informatik, Mathematik oder einer Ingenieurwissenschaft
• Programmierkenntnisse in MATLAB
• Vorkenntnisse in Bilddatenverarbeitung sind hilfreich

Conditions

Beginn: ab sofort
Bearbeitungszeit: 4-6 Monate

Links:

Online application

Please apply online: english / german

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Investigating the effects of surface roughness on the microlayer evaporation of nucleated bubbles

Student practical training / Master theses

Evaporation of microlayer is one of main contributions to the bubble growth. The microlayer is a micro meter scale thin liquid layer underneath a nucleated bubble over heated surface. Heat transfer surface characteristics play a crucial role in the formation and the vaporization of this layer. The effects of surface characteristics, especially the roughness effects on the microlayer thickness did not receive that much research interest. The present study aims to predict the surface roughness effects on the initial microlayer thickness during the microlayer formation and it’s contribution to the bubble growth. An experiment will be performed in a borosilicate glass vessel. Bubbles will generate from artificial cavity on a laser treated stainless steel surface. The laser treated surfaces will influence the microlayer formation and bubble growth. An empirical expression will be developed to capture the initial microlayer thickness as a function of surface roughness profile (height in this work).

Investigation process: experimental and numerical

- Capturing nucleated bubble of degassed deionized water using high-speed imaging techiques for different heaters
- Processing the captured results using image processing tools
- Consideration of uncertainities related to experiment and data processing
- Analyzing experimental data setup
- Numerical calculation of associated heat transfers using MATLAB
- Development of an empirical correlation based on experimental data.

Department: Experimental Thermal Fluid Dynamics

Contact: Sarker, Debasish, Dr. Ding, Wei

Requirements

• Academic studies in the field of process engineering, chemical engineering, mechanical engineering or comparable fields of study.
• Knowledge in heat and mass transfer phenomena
• Expertise in MATLAB or similar coding

Conditions

• Literature research – nucleate bubble dynamics
• Experiment using imaging techniques
• Processing the experimental results
• Analyzing the results

Online application

Please apply online: english / german

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Feasibility of a renewable powered N-fertilizer pro-duction in Germany

Student practical training / Bachelor theses / Master theses / Diploma theses

As part of the Energiewende, the Institute for Fluid Dynamics at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) is adapting energy intensive processes for the production of chemicals to be supplied only with electricity from renewable resources.
Ammonia is the second most produced chemical worldwide and the basis of all nitrogen-based fertilizers. Novel production paths include the combination of Haber-Bosch synthesis and water electrolysis as well as solid state ammonia synthesis.
The objective of the thesis is to evaluate the technical feasibility of operating an ammonia production facility using one of the aforementioned technologies in combination with a renewable energy source.

Tasks:
• Collect data on ammonia production using renewable energies.
• Conduct an energy balance of a wind farm/solar farm capable of covering all electricity and N-fertilizer needs.
• Evaluate the combined use of battery storage and wind turbines for an island grid.
• Assess the feasibility of producing fertilizers other than ammonia using also renewable energies.

Department: Experimental Thermal Fluid Dynamics

Contact: Dr. Rodriguez Garcia, Gonzalo, Dr. Kryk, Holger, Prof. Dr. Hampel, Uwe

Requirements

• Student of Chemical, Process or Electrical Engineering, Energy Technology (Renewable Energy Systems) or similar.
• Experience with Aspen Plus, ChemCAD or similar is not required, but desirable.
• High level of English.

Conditions

• 4-6 Months
• Starting as soon as possible

Online application

Please apply online: english / german

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Experimental visualisation of particle-bubble interactions

Student practical training / Bachelor theses / Master theses / Diploma theses

Froth flotation is a separation process which plays a major role in the mining industry. Bubble-particle interactions are the very heart of this process, largely used for the capture of valuable commodities such as rare earth metals. The Institute of Fluid Dynamics of the research centre Helmholtz-Zentrum Dresden-Rossendorf (Germany) is making a bold move towards investigating the capture of mineral particles by rising bubbles. The Institute seeks a student to deploy high-speed imaging techniques and to observe the collision and attachment of particles falling on a bubble surface.

Tasks:
•Literature survey on particle attachment to bubble surface and froth flotation
•Visualisation with a high-speed camera of the attachment of falling solid particles on the surface of bubble
•Image processing of particle-bubble interactions

Duration: 6 Months

Financial compensation: yes

Language course: The HZDR offers German courses free of charge (not compulsory)

International applications: Yes, we welcome international applicants. It is preferable if the present internship is a compulsory part of your studies.

References
[1] Lecrivain G., et al., Attachment of solid elongated particles on a gas bubble surface. International Journal of Multiphase Flow 71, p. 83-93, 2015
[2] Lecrivain G., et al., Direct numerical simulation of a particle attachment to an immersed bubble. Physics of Fluids 28, 083301, 2016

Department: Experimental Thermal Fluid Dynamics

Contact: Dr. Lecrivain, Gregory

Requirements

•Interest in fluid mechanics
•High level of autonomy
•Enthusiasm for experimental work

Online application

Please apply online: english / german

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Tracking of autonomous, flow following sensor particles

Master theses / Diploma theses / Student Assistant

Foto: AutoSens_StirredReactor ©Copyright: fwdf (Mailgruppe)Autonomous flow following sensor particles are used for acquisition of spatially distributed process parameters in industrial processes, such as biogas digesters, waste water treatment basins or bioreactors. The task is focussed on the development of algorithms for reconstruction of the 3D movement trajectory of sensor particles based on data from the onboard inertial sensors, namely acceleration, angular rate and magnetic field, and an additional sensor for vertical position as function of the hydrostatic pressure. A favored approach is based on inertial navigation techniques that apply Bayes filters, e.g. Kalman filters, to fuse the sensor data. The developed algorithms are to be validated experimentally.

Department: Experimental Thermal Fluid Dynamics

Contact: Dr. Reinecke, Sebastian

Requirements

• study programs in the fields of electrical engineering, mechatronics, mechanical engineering and related degree programs
• fundamentals of digital signal analysis, Bayes' filters, Kalman-filters, rigid body motion
• experimental skills
• data analysis in Matlab, Octave or C/C++
• self-regulating, independent work methods

Links:

Online application

Please apply online: english / german

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Charakterisierung des Stofftransports in einer Blasenströmung anhand tomographischer Daten

Student practical training / Master theses / Diploma theses / Student Assistant / compulsory internship

Blasensäulen sind aufgrund ihrer einfachen Bauweise ein beliebter Reaktortyp in der chemischen Industrie. Vor allem die Hydrodynamik und der Stofftransport in Blasensäulen sind für den Umsatz und die Selektivität chemischer Reaktionen von Bedeutung. In einer Blasenströmung wurden Messungen mit der ultraschnellen Röntgentomographie zum Stofftransport durchgeführt, welche nun genauer analysiert werden sollen. Ziel ist es charakteristische Größen für den Stofftransport und die Hydrodynamik zu extrahieren. Dazu sind vorhandene Auswertealgorithmen anzupassen und ggf. zu erweitern.

Department: Experimental Thermal Fluid Dynamics

Contact: Kipping, Ragna

Requirements

Online application

Please apply online: english / german

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Untersuchungen der Hydrodynamik von dispersen Zweiphasenströmungen in komplexen Geometrien

Student practical training / Diploma theses / Student Assistant

Zweiphasenströmungen sind ein wesentlicher Bestandteil industrieller Anwendungen im Bereich der Wärmeübertragung, der chemischen Industrie oder der Kraftwerkstechnik. Häufig weisen die durchströmten Komponenten solcher Anlagen komplexe geometrische Bedingungen auf. Für einen sicheren und effizienten Betrieb ist die genaue Kenntnis der Hydrodynamik der resultierenden Strömungsvorgänge von essentieller Bedeutung. Dafür sollen experimentelle Untersuchungen mittels der ultraschnellen Röntgentomographie an einer thermohydraulischen Versuchsanlage durchgeführt werden. Ziel ist es einen Beitrag zur Beschreibung komplexer Strömungsvorgänge zu liefern.

Department: Experimental Thermal Fluid Dynamics

Contact: Neumann, Martin

Requirements

• Studium des Chemie-Ingenieurwesen, Verfahrenstechnik, oder ähnlichen Ingenieurstudiengängen
• Kenntnisse im Bereich der Datenauswertung mit Matlab von Vorteil
• Freude am experimentellen Arbeiten

Online application

Please apply online: english / german

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Parallelisation of an algorithm for projection data reassignment

Student practical training / Bachelor theses / Student Assistant

With the spatial high resolution gamma-ray computed tomography measurement system for high energy gamma radiation (662 keV) dense objects with up to a diameter of 700 mm can be no-destructively analysed with an in-plane resolution of approximately 2 mm. The available single core C++ program (32-bit compiler) has to be analysed concerning parallelisation, i.e. multi core CPU and/or many core GPU) and has to be optimised.

Department: Experimental Thermal Fluid Dynamics

Requirements

- Handling with CUDA (NVIDIA)
- Handling with LINUX UBUNTU
- Advanced mathematic knwoledge

Links:

Online application

Please apply online: english / german

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Implementation of a performance optimized ray reassignment algorithm

Student practical training / Bachelor theses / Student Assistant

With the available ultrafast X-ray electron beam computed tomography scanner of the HZDR up to 8000 non-superimposed cross-sectional images can be contactless obtained per second. For an effective implementation of standard reconstruction algorithms a ray reassignment must be performed on GPUs.

Department: Experimental Thermal Fluid Dynamics

Requirements

- Handling with CUDA (NVIDIA)
- Handling with LINUX Ubuntu
- Advanced mathematic knowledge

Links:

Online application

Please apply online: english / german

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Experimental studies on the partial oxidation of Isobutane with oxygen in a micro reactor, as well as their analysis.

Student practical training / Bachelor theses / Master theses / Diploma theses / compulsory internship

The Institute of fluid dynamics in the Helmholtz-Zentrum Dresden-Rossendorf (HZG) deals among other things with the experimental investigation and simulation of chemical processes of multi phase.
In the framework of the energy Alliance project "energy-efficient chemical multiphase processes" examines the partial oxidation of Isobutane in liquid or of supercritical phase with oxygen by means of a specially designed micro reactor to TBHP. This to the influence of different initiators, pressures, temperatures, additives and reactant ratios etc. are examined. The reaction product is analysed using gas chromatography mass spectrometry (GC-MS).
The Working Group process chemistry of Department experimental Tuhh offers for one or two semester students of the departments of chemical engineering, chemistry, physics, engineering, or similar professional orientation activities with a focus on technical, analytical, and physical chemistry.

Analytical examinations by GC-MS.

Ø Studies on the stability of the samples, reproducibility, precision and accuracy of measurements and evaluation.

· Performing the reaction under variation of one of the specified parameters.

Ø Response technical studies on the influence of one of the above reaction parameters and evaluation.

· Performing the reaction under variation of one of the specified parameters.

Ø Response technical studies on the influence of one of the above reaction parameters and evaluation.

Department: Experimental Thermal Fluid Dynamics

Contact: Dr. Willms, Thomas, Dr. Kryk, Holger

Requirements

• Student of the departments of chemical engineering, chemistry, physics, engineering or similar professional orientation.
• High accuracy and care at work.
• Hard work and joy in experimental work.
· Student of the departments of chemical engineering, chemistry, physics, engineering or similar professional orientation.

Conditions

at least 5 month, begin as of now possible

Online application

Please apply online: english / german

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Liquid mixing and mass transfer measurements in a bubble column reactor with internals

Student practical training / Bachelor theses / Master theses / Diploma theses

Bubble column reactors are apparatuses of choice regarding multiphase flows/reactions in the chemical process industry. Processes like the Fischer-Tropsch-synthesis are typically carried out in a bubble column reactor. Since most of the reactions are of exothermic nature, the produced heat has to be sufficiently removed to guarantee a stable reactor operation. Therefore, longitudinal flow heat exchanging tubes, which alter the flow behavior of the phases and cover a large portion of the reactor’s cross sectional area, are inserted into the bubble column reactor. For a secure construction of a bubble column with an internal tube bundle heat exchanger, its influence on hydrodynamic, mass transfer and liquid mixing needs to be investigated.

Department: Experimental Thermal Fluid Dynamics

Contact: Möller, Felix

Requirements

• Student of Process or Chemical Engineering, Technical Chemistry or comparable fields of study
• Enthusiasm in experimental work
• Knowledge in plant commissioning and mass transfer phenomena are welcome, but not compulsory
• Knowledge in Matlab for data acquisition

Conditions

• Literature research in the field of bubble column reactors with internals and measurement techniques
• Investigation of liquid mixing and mass transfer in bubble columns with internals using oxygen proebes and wire-mesh sensors
• Measurement of mass transfer in bubble column with internals
• Model development for bubble columns with internals, maybe compartment modeling

Links:

Online application

Please apply online: english / german

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Untersuchung des Einflusses von Regularisierungsmethoden auf Bildrekonstruktionsalgorithmen

Student practical training / Bachelor theses / Master theses / Diploma theses

Bei der tomographische Bildrekonstruktion muss ein diskretes inverses Problem gelöst werden, wofür algebraische Methoden wie zum Beispiel ART und CG-Verfahren verwendet werden können. Dabei spielt die Regularisierung, die den Einfluss von Diskretisierungsfehler und Messdatenrauschen auf die Lösung beschränkt, eine entscheidende Rolle. Deren Einfluss auf die Bildrekonstruktion von Röntgen- und Gamma-CT-Messdaten soll untersucht werden. Dazu sind folgende Teilaufgaben zu lösen:
• Implementierung verschiedener Regularisierungsmethoden
• Anwendung der Programme auf Messdaten
• Parameterstudien um die Regularisierungsmethoden für die Messdatensätze zu optimieren.

Department: Experimental Thermal Fluid Dynamics

Contact: Wagner, Michael, Dr. Bieberle, Martina

Requirements

• Programmierkenntnisse in MATLAB
• Grundkenntnisse zur numerischen Behandlung linearer Gleichungssysteme

Links:

Online application

Please apply online: english / german

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