Email: 

christopher.bernardy(at)bam.de

Supervisors:

Dr. Karim Habib (BAM)

Prof. Dr. Alessandro Orchini (Technical University Berlin)

Research topic:

Large scale safety investigation of hydrogen jet flames

Abstract:

Since hydrogen is usually stored and transported under pressure, one scenario to be considered is the release of hydrogen from a leakage with subsequent ignition. The resulting jet flame must be characterized with respect to the thermal radiation emitted into the environment to define safety distances. Various models that characterize the resulting flame shape and radiation already exist in the literature, but these are mainly based on empirical data from hydrocarbon jet flames.  To verify the applicability of these models to hydrogen, real-scale tests are carried out at the BAM Test Site for Technical Safety (BAM-TTS) with the aim to assess the flame geometry and the emitted thermal radiation. Parameters such as leakage diameter (currently up to 30 mm), pressure (currently up to max. 250 bar) and mass flow (up to max. 0.5 kg/s) are varied. Existing heat radiation data from literature are mostly based on unsteady outflow conditions. The experimental setup used here allows for the generation of a steady-state outflow and thus a direct comparability with existing (steady-state) models. Following from the experimental investigations, modelling parameters such as the Surface Emissive Power (SEP) and the radiant heat fraction for hydrogen will be compared to literature data.

Short bio:

Since 2023/01 – Ph.D. Student at the Chair of Nonlinear Thermo-Fluid Mechanics, Institute of Fluid Mechanics and Technical Acoustics at the Technical University of Berlin

2018-2021 – M.Sc. Engineering Science (Focus on Fluid Mechanics and Technical Acoustics) at the Technical University of Berlin

2015-2018 – B.Sc. Engineering Science (Focus on Thermodynamics) at the Technical University of Berlin

Email: 

finn-reinhard.harwege(at)bam.de

Supervisors:

Prof. Dr.-Ing. Heiko Schmidt (BTU)

Dr.-Ing. Robert Eberwein (BAM)

Research topic:

Characterisation of Vacuum Insulation-Panel based Insulation for Liquefied Hydrogen Storage

Abstract:

A future use of liquefied hydrogen (LH2) as an energy carrier requires new solutions for the thermal insulation of hydrogen storage tanks. Current medium to large scale tanks utilize a double wall with vacuum and a low thermal conductivity powder as bulk fill between the two tank walls. This offers poor failure resistance and is not economic to build at a large scale.

A promising alternative concept uses vacuum insulation panels (VIP). VIPs consist of a gas tight envelope that surrounds a low conductivity core material, and a vacuum is created in the envelope. The insulation system is then created by surrounding the LH2 tank with multiple layers of VIPs.

While models for heat transfer through VIP-systems exist in the building industry, cryogenic conditions pose new questions. In the project, numerical and analytical models will be developed for the heat transfer and thermo-mechanical behaviour of the system. To validate the models and identify critical parameters, thermal conductivity measurements through insulation system prototypes at cryogenic temperature and relevant scale will be performed. Additionally, mechanical, and thermal tests on single VIPs will be carried out. The created models are important for the evaluation and dimensioning of VIP systems for cryogenic storage.

Short bio:

• Bachelor of Science in Mechanical Engineering at TU Berlin, Germany
• Master of Science in Engineering Sciences at TU Berlin, Germany (Focus on Fluid Dynamics and Simulation)

Email:

josua-kondja.junias(at)bam.de

Supervisors: 

Dr.-Ing. Enis Askar (BAM)

Dr.-Ing. Kai Holtappels (BAM)

Dr. Erasmus Shaanika (UNAM)

Research topic:

Prediction ofExplosion Characteristics of Hydrogen Mixtures using Machine Learning Models

Abstract:

An understanding of fuel/oxidizer/diluent gas mixtures explosion characteristics and their accurate prediction is crucial for ensuring the safety of hydrogen-related applications, reducing accidents risk, and protecting lives and property. For the prediction of explosion limits, detonation cell sizes and detonation run-up-distances, various empirical, semi-empirical and numerical models can be found in literature, usually limited to narrow ranges of process or geometrical parameters. Moreover, based on the limited availability of the detonation cell widths measurements, current estimation models are seemingly inaccurate. Machine learning models can be utilized to make justifiable prediction on the detonation cell sizes of hydrogen-air mixtures and other gaseous explosive mixtures cell sizes, explosion limits or run-up distance based on the mixture type, temperature, pressure, equivalence ratios as well as on geometrical parameters with consideration of highly diverse experimental data measurements uncertainties. Therefore, up-to date databases for explosion characteristics will be established and machine learning models will be developed, trained, tested, and validated using experimental data to predict explosion characteristics of hydrogen mixtures. It will be tested whether machine learning models are able to predict the explosion characteristics of hydrogen mixtures with a higher accuracy and more comprehensively than conventional empirical and numerical models from literature.

Short bio:

Junias Josua Kondja journey is marked by a profound commitment to both academic excellence and societal impact. Born and raised in Okahao, Namibia, his academic journey started at the University of Namibia (UNAM), where he pursued and obtained a Bachelor's (Honours) degree in Mechanical Engineering in 2020. His passion for exploring the intersection of engineering and innovation led him to pursue and obtain a Master of Science degree in Mechanical Engineering in 2023. In this study, he had focused on modelling and investigating the effects of general asymmetries on the vertical transferred imposed forces onto road surfaces, addressing the issue of pavement deterioration from heavy vehicles. His dedication to advancing knowledge and making a positive impact on society is further exemplified by his current pursuit of a Ph.D. in Mechanical Engineering, specializing in hydrogen combustion safety, and incorporating machine learning techniques. Junias envisions a future where safety and sustainable energy solutions are accessible to all, and his research aims to establish secure methods for utilizing combustible energy carriers such as hydrogen and its derivatives. Outside of academia, Junias enjoys architectural sketching and watching football and other documentaries. These interests provide him with relaxation opportunities and creativity, complementing his engineering pursuits by fostering a well-rounded perspective. Junias Josua Kondja's trajectory embodies a commitment to academic excellence, innovation, and social responsibility.

Email:

reinhold.leo(at)bam.de

Supervisors:

Prof. Dr.-Ing. Thomas Bollinghaus (BAM)

Dr. Oded Sobol (BAM)

Dr. Ester Hango

Research topic:

Compatibility of Duplex Stainless Steels for Gaseous Hydrogen Applications

Abstract:

The key to implementing the usage of clean energy sources is the construction of energy storage and transportation infrastructure. It is necessary to have safe infrastructure, such as transportation pipelines made of various sustainable alloy steels. Duplex stainless steel (DSS) alloys are an essential component used in the construction of transportation pipelines because of their many distinctive qualities. To ascertain if DSS is suitable for high-pressure gaseous hydrogen applications, the interplay between several critical parameters that result in Hydrogen Embrittlement or Hydrogen Assisted Cracking was examined using high-pressure hydrogen charging, Electron Backscatter Diffraction, and hydrogen concentration measurements using Carrier Gas Hot Extraction . It was determined whether strain-induced martensitic transformation of austenite was present in a DSS 1.14462  in-service pipe taken from a hydrogen refuelling station, and in samples of freshly charged DSS 1.4462. No major direct martensitic phase transformation of the austenite phase under a high hydrogen pressure environment was observed. Future experiments include the assessment of the impact of high-pressure gaseous hydrogen on the welded components, and under mechanical load via the hollow (tubular) specimen technique.

Short bio:

Reinhold Leo was born in Oshakati and raised by his parents in a village called Amutanga-Oshana Region, Namibia. He graduated with a Bachelor of Engineering Degree in Metallurgy from Namibia University of Science and Technology, in 2017. He further enrolled for postgraduate studies in Business Administration, Industrial Engineering and Management Development.

Reinhold started his professional career as a Graduate Metallurgist, at a specialised complex copper concentrate smelter in Tsumeb, Namibia owned by Dundee Precious Metals.  Over 6.5 years, he gained and continued developing various technical & operational skills tailor-made for problem-solving in the metallurgy and materials science fields.

The complex nature of the smelter, his passion for solving industrial problems, and his contribution to the scientific body of knowledge inspired him to take up doctoral studies where he currently researches advanced materials, with special emphasis on innovative steels, and components safety for alternative energy carriers.

Apart from the busy schedules, Reinhold enjoys spending time with his children, Justine, and Zaine; and watching soccer.

Email:

andreas-sheuyange.namwoonde(at)bam.de

Supervisors:

Prof. Dr.-Ing. Thomas Boellinghaus (BAM)

Dr. Géraldine Theiler (BAM)

Prof. Oluwagbenga Johnson (UNAM)

Research topic:

Compatibility of composite and polymer materials for tribological applications in gaseous and liquid Hydrogen

Abstract:

The adoption of Hydrogen as an alternative energy source to fossil fuels requires compatible materials for safety reasons in hydrogen. Thermoplastics are widely applied in areas with tribological concerns, owing to their exceptional characteristics. Polymer composites are valued across industries due to their lightweight, corrosion resistance, customizable design, and stable thermal properties, making them suitable for application as dynamic sealants in high-pressure and liquid hydrogen systems for safety reasons.

This project will investigate the compatibility of high-performance polymers and polymer composites for application in gaseous and liquid hydrogen by evaluating their tribological properties. Good candidates as materials for production tribological parts in hydrogen environment, should be able to provide self-lubrication and wear resistance in these extreme conditions subjected to high pressure and extreme cold temperature.

Short bio:

Andreas was born in Endola village, Northern Namibia. He obtained a Bachelor's and Master of Engineering in Chemical Engineering from Mendeleev University of Chemical Technology, Moscow, Russia.

Afterwards, he started working for the University of Namibia (UNAM) as a lecturer for Inorganic Chemistry and later became a Renewable Energy Researcher at SAMUMARC in Henties Bay, a research centre of UNAM. Under this role, he carried out research work on Biogas production from agricultural and domestic wastes. At the same time in Henties Bay, he was a caretaker for Henties Bay Aerosol Observatory (HBAO) a multinational research corroboration project, which housed several climatological research equipment for aerosol measurements.

In June 2023 under BAM-UNAM corroboration, he relocated to Berlin to carry out his Ph.D. research work at the Bundesanstalt für Materialforschung und -prüfung (BAM) at division 9.0 Component Safety. 

Email:

sam.shaanika(at)bam.de

Supervisors:

Dr. Thomas Alweendo (UNAM)

Dr. Oded Sobol (BAM)

Prof. Dr.-Ing. Thomas Böllinghaus (BAM)

Research topic:

Compatibility of welded austenitic stainless steels (316L) for green hydrogen application

Abstract:

In the energy transition towards a low carbon economy, Namibia strives to produce green hydrogen and its derivatives from the plentiful renewable resources such as solar, wind and sea water. The supply value chain of hydrogen requires compatible and safe materials (Metal and non-metals) used are prone to hydrogen embrittlement which tend to reduce ductility and fracture toughness and increase in crack growth rate. In this study structural integrity assessment of 316L in the cold drawn and annealed states will be performed using the welded and none-welded specimens in the slow strain tensile and burst pressure testing. The tubular specimens are examined in hydrogen or air. The specimens were high pressure gaseous hydrogen precharged or argon at the 1000 bar, 150℃ for 20 days. The effect of hydrogen on the mechanical properties of the base materials, weldment and heat affected zone were determined. Finally, the quantification of the hydrogen embrittlement index for the susceptibility and compatibility of material for green hydrogen application.

Short bio:

Sam Shaanika was born in Oneheke village, Omusati Region northern Namibia. He obtain his Bachelor and Master of Science degrees in Mechanical Engineering from the Beijing Jiaotong University in Beijing, China in 2009 and 2011 respectively. Upon returning to Namibia, He joined the University of Namibia as an academic staff based at the Faculty of Engineering and Information Technology, JEDS Campus in Ongwediva Town, Oshana Region. He has been involved in the teaching, research and community engagement activities since September 2011 to date.  Some of the courses He taught are Engineering drawing, Operations Management, machine Tools, Manufacturing Technology and Renewable energy. From 2016 to 2021 He served as the Head of department for the Workshops and Industrial training responsible for industrial placement of students and staff for Internships, organising excursions and Industrial engagement activities such as Industrial day, open day, trade and career faith exhibition and participation of the Faculty and formalising collaborations (MoU) with stakeholders.  In 2014, He was awarded the UNESCO fellowship for 6 months at AGH University in Krakow, Poland with research on transportation systems and robotics. He obtained various internships exposures at Industries such as Ohorongo Cement (Manufacturing), RITC (NDT), Namwater at Oshakati (canal sediment removal) and Grunau (Desalination). In Pursuit to advance His academic career, He was awarded the PhD BAM-UNAM scholarship June 2023-June 2026 based at BAM, Unter den Eichen campus, Berlin with research focusing on the Compatibility of Welded Austenitic stainless steels for hydrogen applications in department 9. Component safety.

Email:

nikanor.shikomba(at)bam.de

Supervisors:

Prof. Thomas Boellinghaus (BAM)

Research topic:

Compatibility of welded low-alloy steel under lower load gh2 application.

Abstract:

The green hydrogen value chain necessitates structural facilities that ensure optimum safety and reliable structural integrity. Structural materials are exposed to an intense hydrogen environment, which creates a conducive condition for hydrogen embrittlement. However, the susceptibility of structural materials to hydrogen-induced embrittlement remains poorly understood. Consequently, further study is necessary to elucidate the embrittlement behaviours of these materials under a hydrogen environment.

Common welded low-alloy steel EN10028 and EN10225-1 are investigated for hydrogen structural compatibility under tensile stress. A slow strain rate test (SSRT) is performed on a hollow tensile specimen using an in-situ charging technique to evaluate the impact of hydrogen on the mechanical properties of the investigated materials. Fractographic analysis of the fracture surface is carried out to correlate the mechanical behaviour to the microscopic deformation of the materials.

In this study, a comprehensive test is currently conducted to gather valuable data and insights. The study aims to investigate and compare the impact of hydrogen on the mechanical and microstructural properties of two welded low-alloy ferritic steels. The results will provide insights into the phenomena of embrittlement and its severity. Thereby contributing to the understanding of the structural integrity of the steel grades under investigation.

Short bio:

• Bachelor of Technology in Mechanical Engineering, Polytechnic of Namibia
• Post Graduate Diploma in Project Management, Management College of Southern Africa (MANCOSA)
• Master’s degree in industrial engineering, University of Science and Technology (NUST), Namibia