Practical trainings, student assistants and theses
Internship - Wastewater Treatment Plant Flexibilization (Id 291)
Compulsory internship
Background:
Uncertainty in influent quantity and quality related to increasingly extreme weather events is an expected outcome of climate change that will severely affect the design and operation of wastewater treatment systems. On top of this, the transition to renewable, weather dependant energy sources required to fight climate change will cause energy availability and prices to fluctuate much more than in the past. New approaches to wastewater treatment plant control are needed to ensure reliable performance and minimal operational costs in the face of such uncertain boundary conditions.
Tasks:
- Collection and analysis of online-available data sources (weather and energy markets)
- Running of wastewater treatment plant operation simulations for different scenarios
- Result assessment with the aim of increasing system reliability and cost-efficiency
Department: Experimental Thermal Fluid Dynamics
Contact: Parra Ramirez, Mario Alejandro, Dr. Reinecke, Sebastian
Requirements
- Currently enrolled in M.Sc. programme on environmental engineering, chemical engineering, biochemical engineering, or a similar field with relevant knowledge on wastewater treatment and management
- Experience with simulation tools for wastewater treatment plants (ASM/BSM models, SIMBA) is desirable
- Enthusiasm for working independently in international and interdisciplinary teams on scientific projects
- Experience on the preparation of scientific reports and effective communication of research results
- Proficiency in English is required, knowledge of German is desirable
Conditions
- A vibrant research community in an open, diverse, and international work environment
- Scientific excellence and extensive professional networking opportunities
- Salary during the internship period
Online application
Please apply online: english / german
Simulation of gas-solid-liquid flows in stirred tanks (Id 290)
Bachelor theses / Master theses / Diploma theses / Student Assistant / Compulsory internship
Multiphase flows with particles and bubbles play an important role in many process engineering applications. Use of CFD („Computational fluid dynamics“) methods offers the possibility to identify energy- and resource-efficient solutions for scale-up and intensification of such processes, which are costly and time-consuming to investigate by conventional semi-empirical methods. Such simulations on the scale of technical equipment are feasible within the Euler-Euler framework, where phenomena on the scale of individual bubbles or particles are modeled. The development of such closure models is a focus of the research in the CFD department of the Institute of Fluid Dynamics at HZDR.
The topic of the present work is the combination of already established models for bubbly or particulate two-phase flows to a model for three-phase flows in which both bubbles and particles are present. To validate this model, simulations are run using ANSYS CFX and compared to experimental data from the literature. The degree of agreement between both is discussed and hypotheses for eventual deviations are suggested. Since our group has many years of experience with this procedure, good chances for quick accomplishment are provided.
Subtaks to work on are the following:
• systematic literature research on experimental databases
• running simulations
• evaluating and documenting the results
• eventually implementation of improved models
Department: Computational Fluid Dynamics
Contact: Dr. Rzehak, Roland
Requirements
• knowledge on fluid dynamics
• experience with ANSYS CFX is advantageous, but can also be acquired if committment is there
• Englisch language skills in writing and speech
• excitement about scientific work
Conditions
• duartion: 4-6 months
• begin: immediately
• compensation
Online application
Please apply online: english / german
Entwicklung eines Gerätetreibers unter LabVIEW (Id 289)
Student practical training / Volunteer internship
Es soll eine UDP-Kommunikation zum Steuerungsmodul eines Laserdiodentreibers entwickelt werden. Das Protokoll ist herstellerseitig vorgegeben.
In LabVIEW müssen die Funktionen des Gerätes abgebildet werden. Ein Demo-Gerät ist vorhanden und kann als Gegenstelle für Programmierung und Test genutzt werden. Die zu entwickelnde Bibliothek muss modular gegliedert sein, so dass eine Integration des Codes in ein übergeordnetes Programm leicht möglich ist.
Department: Instrumentation
Contact: Wagner, Nicole
Requirements
- Grundkenntnisse LabVIEW
- Grundkenntnisse Netzwerkkommunikation
Conditions
Start ab sofort möglich
Online application
Please apply online: english / german
Image processing for surface flow tracking (Id 288)
Compulsory internship
Background:
Mixing and homogeneity in large vessels, such as in biogas digesters and wastewater oxidation basins, determines stability, efficiency and productivity of the processes. However, achieving efficient mixing of the huge reactor volumes is a big challenge, since there is a lag of monitoring methods to characterize the flow patterns inside the closed vessels.
Objective:
The project focusses on the development of image processing algorithms for surface flow tracking. Sample images of typical flow behavior are captured by a conventional camera system continuously. These data sets shall be used to develop the tracking algorithms for surface flow, floating layer and homogeneity preferably with available software toolboxes, e.g. imagej, U-net, octave or others.
Tasks:
- Survey on flow imaging toolboxes
- Definition of target parameters for data extraction
- Screening of available sample data sets
- Implementation of imaging processing and data extraction routines
- Documentation and presentation of results
Department: Experimental Thermal Fluid Dynamics
Contact: Dr. Reinecke, Sebastian
Requirements
Studies in the area of computer science, informatics, electrical, mechanical engineering or similar
• Comprehensive knowledge of digital image analyses (optical flow, pattern recognition)
• Basics of machine learning based image processing (e.g. U-net)
• Independent and structured way of working
Online application
Please apply online: english / german
Fachgebiet Maschinendynamik - Theoretische Schwingungsanalyse eines MRI-Versuchsstandes (Id 286)
Student practical training / Master theses / Diploma theses
Schwingungsanalyse
Das Maschinenkonzept ist durch um eine vertikale Achse rotierende Teile in Form eines zylindrischen Behälters mit Einbauten charakterisiert. Der Schwingungsanalyse kommt dabei eine wesentliche Rolle zu. Ohne vorherige numerische Berechnung der Eigenfrequenzen der rotierenden Bauteile, die letztlich das ganze Maschinenverhalten bestimmen, und dem Ergreifen geeigneter konstruktiver Maßnahmen zur Dämpfung der Eigenschwingungen ist es unmöglich, eine betriebssichere Maschine herzustellen.
Diese Eigenfrequenzen können numerisch berechnet werden, wobei das Berechnungsspektrum alle Betriebszustände umfasst (Hochlauf auf Nenndrehzahl, Betrieb auf Nenndrehzahl, Stopplauf, Änderung der Betriebsdrehzahl, etc.). Aus den berechneten Frequenzen können nach eingehender Bewertung von Amplitude und Schwingungszustand geeignete konstruktive Maßnahmen abgeleitet werden, sodass ein Systemversagen durch eine Resonanzhavarie ausgeschlossen werden kann.
Zur Untersuchung der dynamischen Einflüsse zum Schwingungsverhalten der Versuchsanlage soll eine Berechnung mechanischer Schwingungen am Gestell mit einem zu erstellenden Rechenmodell erfolgen. Daraus abgeleitet sollte eine Abschätzung zu zulässigen Unwuchten bzw. anzubringenden Auswuchtgewichten der Versuchsmaschine getroffen werden.
Die theoretische Schwingungsanalyse für den Entwurf der MRI-Maschine soll als Parameter-Studie mit der Finite Elemente Methode (FEM) durchgeführt werden. Das Ziel ist, herauszufinden, wie sich die Eigenfrequenz der Maschine in Abhängigkeit der Parameter ändert.
Für die FEM - Berechnung ist ein geeignetes Modell zu finden. Unter rein mechanischen Gesichtspunkten sind die kritischen Drehzahlbereiche der Versuchsanlage anhand einer Parameterstudie abzuschätzen. Die zu variierenden Parameter sollen den Einfluss der Lageranordnung, der Masse des Überhanges und die Steifigkeit der Wellen berücksichtigen.
Hinsichtlich möglicher Einflussgrößen wie Lagerreibung und Aerodynamik soll eine Abschätzung für die Leerlauf- und die Nennleistung bei höheren Geschwindigkeiten erfolgen.
Neben räumlichen Gegebenheiten sind überlagerte Momente charakteristisch für die Aufgabenstellung.
Institute: Department of Research Technology
Contact: Dr. Steglich, Christian, Köppen, Sebastian
Requirements
Kenntnisse: FEM-Berechnung
Conditions
Beginn: ab sofort
Online application
Please apply online: english / german
6-month internship on the experimental investigation of granular mixing (Id 285)
Student practical training / Bachelor theses / Master theses / Diploma theses / Compulsory internship / Volunteer internship
Background:
Granular mixing is an important industrial process. In the pharmaceutical industry for instance, the powder that is pressed to make tablets is produced by mixing precise quantities of active substances and excipients in granular state. The mixing needs to be done in such a way that the final powder has a homogeneous composition. Tablets may also need to be coated in a pan coater. Granular mixing also plays a crucial role there, as it greatly affects the thickness of the coating. Granular mixing is also often coupled with heat exchanging and solid-gas or solid-solid reactions, as is the case of rotary kilns in the cement, ceramics and metallurgical industries. The quality of the mixing is then a crucial factor to the efficiency of the overall process.
Objectives:
The objective of the work is to experimentally study the mixing process of two different types of granular particles inside a rotating drum under various operating conditions. More specifically, the mixing process is to be captured with a high-speed camera. The videos are then to be post-processed in order to extract characteristics of the particle velocity fields and mixing efficiency. The mixing facility is already available.
Tasks:
• Literature survey
• Mixing experiments under various operating conditions
• Post-processing of the results with MATLAB
Department: Experimental Thermal Fluid Dynamics
Contact: Papapetrou, Theodoros Nestor
Requirements
• Student of natural sciences or engineering
• Willingness to conduct experimental work
Conditions
Duration: 6 months
Remuneration: available
Online application
Please apply online: english / german
Entwicklung neuer Radiopharmaka für die zielgerichtete Tumortherapie mit Alphaemittern (Id 283)
Student practical training / Bachelor theses / Master theses / Diploma theses / Compulsory internship / Volunteer internship
Die gezielte Behandlung von Tumorerkrankungen erlangt zunehmend an Bedeutung. Die eng mit der radiopharmazeutischen Forschung verknüpfte Nuklearmedizin ist auf die Anwendung radiomarkierter Verbindungen (Radiopharmaka) für die Tumordiagnostik und -therapie spezialisiert. Dabei wird ein bestimmtes Radionuklid entweder direkt am Molekül oder stabil in einem Komplexbildner gebunden und an ein biologisch aktives Molekül geknüpft (Peptid, Antikörper...). Das Radiopharmakon bindet dann spezifisch an bestimmten Zellen (z.B. Knochenzellen, Tumorzellen...). Während zur diagnostischen Bildgebung Gamma- und Positronenemitter eingesetzt werden, kommen für therapeutische Anwendungen ausschließlich Betaemitter und Alphaemitter zum Einsatz. Vor allem letztere zeichnen sich dadurch aus, Krebszellen höchst effizient zu zerstören und gleichzeitig das umliegende Gewebe bestmöglich zu schonen. Nennenswerte Vertreter der Alphaemitter sind die beiden Radiumisotope Radium-223/-224 sowie Actinium-225. Für Radium-223/-224 existiert mit Barium-131 ein in unserer Gruppe etabliertes, diagnostisches Analogon, welches im gleichen Konjugat anwendbar ist.
In diesem Forschungsprojekt sollen neue Chelatoren für Barium und Radium auf Basis von Azakronenethern synthetisiert werden. Das Hauptziel ist es, anschließend die Radiomarkierung dieser Chelatoren zu testen und zu optimieren. Der vielversprechendste Chelator wird dann schlussendlich an ein Biomolekül gebunden, um biologische Untersuchungen in vitro und in vivo zu ermöglichen.
Department: Radionuclide Theragnostics
Contact: Reissig, Falco
Requirements
- Studium der Chemie oder eines artverwandten Studiengangs
- Erfahrungen im Bereich der Synthesechemie und Analytik
- Interesse an der wissenschaftlichen Arbeit in einem interdisziplinären Team
- Bereitschaft zum Umgang mit Radioaktivität
- Gute Kommunikationsfähigkeiten in Wort und Schrift (deutsch & englisch)
Conditions
- Beginn ist nach Absprache ab sofort möglich
- Praktikumsdauer mindestens 8 Wochen
- Vergütung nach internen HZDR-Regelungen
Online application
Please apply online: english / german
Contributions to motion tracking of autonomous flow-following sensor particles in industrial process environments (Id 279)
Bachelor theses / Master theses / Diploma theses / Compulsory internship
Data acquisition in large industrial vessels such as biogas fermenters or wastewater treatment plants is limited to local measurement points due to limited access to the vessel and the non-transparency of the fluid. To optimize these kinds of plants, the three-dimensional flow field and the spatial distribution of properties such as temperature and electrical conductivity inside the vessel need to be known. This can be achieved by the autonomous flow-following sensor particles developed by HZDR. Equipped with a pressure sensor, an accelerometer, two gyroscopes and a magnetometer, the sensor particle can track the movement inside the vessels and to infer the flow field from that. The analysis of the data is done after a successful recovery from the vessel. Therefore, algorithms of any complexity can be used to track the motion of the sensor particle.
For the extension and especially for the improvement of the motion tracking we offer the following tasks, from which we can agree on a topic for a thesis or an internship:
• Development of motion tracking algorithms
• Characterization and error correction of the sensors
• Intelligent sampling for the sensors
• Experimental investigation of the maximal acceleration on a stirrer
• Development of firmware to cover several data acquisition scenarios
• Development of an end-user program for the configuration and data analysis of the gathered data
Department: Experimental Thermal Fluid Dynamics
Contact: Buntkiel, Lukas
Requirements
Studies in the area of electrical, mechatronic, mechanical engineering or similar
• Basics of measurement uncertainty, digital signal processing
• Data analysis in Python
• Independent and structured way of working
Conditions
Start possible at any time
Duration according to the respective study regulations
Links:
Online application
Please apply online: english / german
Experimental investigation of the multiphase flow in a stirred tank with PIV and Shadowgraphy (Id 277)
Student practical training / Bachelor theses / Master theses / Diploma theses
With the energy turnaround, the demand for rare earth elements (REE) for key technologies such as lithium for electromobility or neodymium for wind turbines is increasing. The effective processing and separation of these valuable minerals represent a challenge for the mineral industry. One possibility for separation is flotation. Flotation separates the solid particles based on their surface wettability. Hydrophobic valuable particles adhere to gas bubbles and rise as agglomerates. These form a froth which can be skimmed off. The selective separation is influenced by the hydrodynamics in the flotation cell. The efficiency of this process still remains far below the economically and ecologically desired targets for the separation of REE.
Of particular interest are numerical models of flotation cells. In these models, process parameters can be changed much more versatile and easier than in experimental investigations. For this purpose, however, it is necessary to understand the processes taking place in flotation based on experimental studies and also to generate data for the validation of numerical models. In this work, a comprehensive experimental study of multiphase flow in the stirred tank with Particle Image Velocimetry (PIV) and shadowgraphy, concerning flow conditions and material parameters, is to be carried out. The results will help to improve the understanding of multiphase flow within the stirred tank and provide validation data for numerical models.
FOCUS OF WORK
• Investigation of the influence of solid particles and bubbles on the multiphase flow in the stirred tank with PIV and shadowgraphy
• Development of suitable algorithms for data evaluation with MatLab or Python
• Cooperation with CFD department for comparison of experimental and numerical results
Department: Transport processes at interfaces
Contact: Sommer, Anna-Elisabeth
Requirements
• Studies in process/energy/mechanical engineering
• Interest in practical work
• Experience in programming with MatLab or Python is beneficial
• Good written and oral communication skills in English and German
Conditions
• Start: immediately
• Duration: ca. 6 months
Online application
Please apply online: english / german
Design and operation of liquid metal batteries as large-scale storage option (Id 256)
Student practical training / Bachelor theses / Master theses / Diploma theses / Compulsory internship / Volunteer internship
In contrast to conventional batteries, Liquid Metal Batteries feature all liquid anodes (alkaline or alkaline earth metal), cathodes (transition metal or metal) and electrolytes (molten salts) at a temperature between 400 °C and 600 °C. For the operation of liquid metal batteries as large-scale storage option (frequency control and other applications), the design of the storage system and operation strategies (including a battery management system) need to be implemented and tested using exemplary load curves.
Starting point is an existing model of a battery system in Python.
Note: This is an offer suitable for a bachelor, master or diploma thesis or studentic internships.
Do not apply if you already finished your studies!
Department: Magnetohydrodynamics
Contact: Dr. Nimtz, Michael
Requirements
Study of mechanical engineering, physics, mathematics or similar
Basic knowledge of engineering principles.
Good knowledge of a programming language, preferably python.
Conditions
Start: October 2019
Duration: 4-6 months
Paid according to HZDR-internal tariff
Links:
Online application
Please apply online: english / german
Student assistant at the DeltaX School Lab (Id 252)
Student Assistant / Research Assistant
The DeltaX student laboratory makes research at the Helmholtz-Zentrum Dresden-Rossendorf an experience for students. We are looking for tutors who enjoy teaching science, research and technology and who would like to support students conducting their experiments. Apply as a student assistant in the DeltaX school laboratory and become part of a young and open-minded team.
Department: Communication & Media Relations
Contact: Dr. Streller, Matthias, Gneist, Nadja
Requirements
- Study of a scientific subject
- Remaining study duration of at least 2 semesters
- Pleasure in teaching science and research- Good to very good grades
- Very good knowledge of German (C level)
Conditions
- 5 - 10 h / week on whole weekdays
- Start of hiring according to agreement
Links:
Online application
Please apply online: english / german
Materialien für Solarkraftwerke (Id 241)
Bachelor theses / Master theses / Diploma theses
Turmkraftwerke stellen die neueste Generation von Anlagen zur solarthermischen Elektroenergieerzeugung dar. Extrem konzentriertes Sonnenlicht wird dabei auf einen zentralen Absorber gerichtet, der die Wärme auf eine Wärmeträgerflüssigkeit überträgt (s. Foto). Zur Erhöhung des Wirkungsgrades von Turmkraftwerken soll die Arbeitstemperatur von derzeit maximal 550°C deutlich erhöht werden. Dafür sollen werkstoffwissenschaftliche Lösungen weiter verfolgt werden, die im Rahmen eines EU-RISE-Projektes entwickelt wurden.
Als Themen für Graduierungsarbeit werden
i) die Optimierung von optischen und elektrischen Schichteigenschaften
ii) die Verbesserung der Schichthaftung auf Hochleistungslegierungen und
iii) die Komplettierung eines neuen Schichtsystems angeboten.
Zur Charakterisierung der untersuchten Materialien stehen modernste in situ und ex situ Analysemethoden zur Verfügung.
Department: Nanocomposite Materials
Contact: Dr. Krause, Matthias
Requirements
1. Studium der Werkstoffwissenschaften, Physik oder Chemie mit überdurchschnittlichen Leistungen (Notendurchschnitt ≤ 2.0)
2. Interesse und Freude an experimenteller wissenschaftlicher Arbeit
3. Grundkenntnisse in Programmierung und sicherer Umgang mit Büro- und wissenschaftlicher Software
4. Fachkundige Englischsprachkenntnisse
Conditions
Beginn: 1.10.2019, internationale Forschungsumgebung, ortsübliche Aufwandsentschädigung
Online application
Please apply online: english / german
Smart actuation system for flow following µAUV particles for industrial process environments (Id 175)
Master theses / Diploma theses / Compulsory internship
Smart 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 aim of the work is the development of an actuator concept for sensor µAUV-particles for the automatic adjustment of buoyancy (buoyancy) and for buoyancy maneuvers under the condition of small size, minimum energy consumption and high reliability. For this, alternative physical and chemical mechanisms should be considered based on the existing electromechanical solution. There are suitable variants to implement and test. Furthermore, the development of sensor intelligence for the actuators in the sensor particles is an essential part of the task. The developed concepts have to be validated experimentally.
We cordially invite you to an on-site conversation to introduce the topic and to agree on further details. Do not hesitate to contact us, because the way is worth it for you.
What can you expect:
In our department, we offer you an attractive work environment to expand your personal and professional skills. The insight into the diverse R&D projects of the department in the areas of sensor and measuring technology as well as energy and process engineering (among others) and the excellent technical equipment of the laboratories offer optimal conditions for this. The possibility of close contact with competent experienced colleagues plays a central role. As part of student work, we have pursued the approach of structured supervision and associated constructive feedback. This includes regular meetings with your supervisor and intermediate presentations in the form of informal "workshop reports" in the extended audience of interested individuals of the department in order to optimally support you in the successful completion of your project. Furthermore, we are open to support outstanding candidates in their continuing academic qualification, such as in doctoral scholarships or in current or upcoming R&D projects.
Subject-related task spectrum:
• Establishment of the scientific and technical principles of mechanical, physical and chemical principles of action for embedded, actuating components
• Concept development for actuators for taring of sensor particles
• Development of sensor intelligence for situation-dependent, automatic buoyancy, for buoyancy maneuvers and for recovery
• Selection, purchase/ composition and comparison of solution variants
• Minimization of size and energy consumption
• Increased reliability when used in particle-loaded biological substrates
• Development of firmware taking into account existing function routines based on an embedded system with 32-bit data structure (e.g. STM32)
• Conception and realization of suitable test scenarios
• Characterization and comparison of implemented variants with regard to accuracy of taring and reliability in long-term use
Department: Experimental Thermal Fluid Dynamics
Contact: Dr. Reinecke, Sebastian, Buntkiel, Lukas
Requirements
• Studies in electrical engineering, mechatronics, mechanical engineering and similar engineering courses
• Experience in design and (micro) actuator systems
• Experience in programming microcontrollers for embedded systems (e.g. STM32)
• Experience in control electronics for microdrives and board design for embedded systems
• Fundamentals of (micro) actuator systems, movement of rigid bodies, measurement uncertainties, digital signal processing
• Data analysis optionally in Matlab, Octave or C / C ++
• Independent, self-responsible working method
Links:
Online application
Please apply online: english / german
Bestimmung von Geschwindigkeitsfeldern aus tomographischen Bilddaten mittels Kreuzkorrelation (Id 164)
Bachelor theses / Master theses / Diploma theses
Am Institut für Fluiddynamik am Helmholtz-Zentrum Dresden-Rossendorf sind zahlreiche Messverfahren für die Untersuchung von Mehrphasenströmungen entwickelt worden. Eines davon ist die ultraschnelle Elektronenstrahl-Röntgen-Computertomographie, welche mit Aufnahmeraten von bis zu 8000 Bildern pro Sekunde eine dedizierte Aufklärung von Strömungsstrukturen erlaubt. Aufgrund der quasi simultanen Aufnahme von Bilddaten aus zwei Messebenen ergibt sich zudem die Möglichkeit, axiale Geschwindigkeiten zu bestimmen, wofür üblicherweise Kreuzkorrelationsverfahren verwendet werden. Im Rahmen dieser Arbeit sollen die Möglichkeiten dieser Methodik in Hinblick auf die Bestimmung von Geschwindigkeitsfeldern in verschiedenen Strömungsszenarienn analysiert werden.
Folgende Teilaufgaben sind zu lösen:
• Studie zu verschiedenen Varianten der Kreuzkorrelation
• Simulation verschiedener Szenarien und Bewertung der Genauigkeit
• Übertragung der Ergebnisse auf reale Messungen
Department: Experimental Thermal Fluid Dynamics
Contact: Dr. Bieberle, Martina
Requirements
• Studium der Informatik, Mathematik oder einer Ingenieurwissenschaft
• Interesse an Messverfahren und Datenanalyse
• Selbständiges Arbeiten
Conditions
Bearbeitungszeit 4 bis 6 Monate
Links:
Online application
Please apply online: english / german
Untersuchung des Einflusses von Regularisierungsmethoden auf Bildrekonstruktionsalgorithmen (Id 57)
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: Dr. Wagner, Michael, Dr. Bieberle, Martina
Requirements
• Programmierkenntnisse in MATLAB
• Grundkenntnisse zur numerischen Behandlung linearer Gleichungssysteme
Links:
