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Evaluierung eines Human Body Models für Insassensicherheitssimulationen in der Luftfahrt (Masterarbeit)
No full textTowards Virtual Certification of a composite aircraft moveable: an outlook on the background and objective of the AdViCe project
No full textAerodynamic Design of Shock Control Bumps on an Aircraft Considering Structural Constraints
No full textShock control bumps can reduce the overall drag of a modern transport aircraft by reducing the wave drag. In this study, different shapes of static shock control bumps on a laminar wing are aerodynamically analyzed using numerical tools. This design study introduces a novel approach by using structurally feasible shapes constrained to the spoiler positions. This ensures feasible realization possibilities in the future. The robustness, drag reduction in off-design condition, is increased by reducing the overall height of the bump. This robust version of the bump is then implemented on a three-dimensional wing geometry of a modern transport aircraft on up to four spoilers. It is shown that the drag reduction potential varies linearly with the bump width in the investigated range of spoiler extensions. Over a wide range of lift coefficients, the bump robustly reduces drag by up to 2%. Estimated fuel savings of up to 1000 kg can be derived for a flight mission of 9000 km for a long-range wide-body aircraft at cruise conditions of M=0.85
Dynamic Spreadsheet Editor for Knowledge Graphs based on Shape Constraints
No full textKnowledge Graphs (KGs) have become increasingly more important in recent years. As structured representations of knowledge, they enable the semantic connection and integration of large amounts of data and provide a powerful basis for data-driven applications. The growing relevance of KGs is not only reflected in industrial applications, but also in academic research, where they are increasingly understood as a key element of modern information systems.
One problem in the practical use of KGs is access to the data for non-experts in the field. However, domain experts are particularly important in the further development, maintenance and correction of KGs. This thesis aims to develop a tool that closes the gap between knowledge graph users, who are non-experts in this field, and ontology engineers.
In this thesis, ShaclSheet, a JavaScript-based web application, was developed that can generate fully editable tables for a knowledge graph. The table structure is automatically generated by a set of configurations created in advance by Ontology Engineers. The configuration of the tables is based on the constraint language SHACL, which was developed as a validation tool for RDF graphs and offers many possibilities for generating editors.
In the course of this development, a comprehensive requirement analysis was carried out. This was used as the basis for the design and subsequent development of the editor. The central components and functionalities of the editor are presented.
This was followed by a user evaluation of the editor within DLR. This focussed on the simplification and time savings of working with ShaclSheet compared to working with SPARQL queries. For this purpose, tasks were to be completed in both cases and then the difficulty of the respective tasks and the experience of working with ShaclSheet were to be specified in a survey. The evaluation was carried out both quantitatively by measuring the time taken to complete the tasks and analysing the rating on a Likert scale, and qualitatively by analysing the comments made by the test subjects.
Finally, an evaluation of the development of ShaclSheet and an outlook on further questions were given
Contrails and their avoidance
No full textI will give an overview on the physics of contrails, how they form, the phases of their evolution, their radiative and climate impacts, and how their impacts can be mitigated. If there is additional time, I could present something on aerodynamic contrails as well
Cover Picture: Elliptical Silicon Nanowire Covered by the SEI in a 2D Chemo-Mechanical Simulation (Batteries & Supercaps 5/2025)
Full text linkThe Front Cover illustrates silicon nanowires as a promising next-generation anode for lithium-ion batteries. The inset highlights the elliptical shape of the nanowires covered by a solid-electrolyte interphase shell and the lithium concentration distribution inside the nanowire. Notably, the mechanical impact of the shell causes lithium concentration anomalies inside the nanowires. More information can be found in the Research Article by R. Schoof, L. Köbbing and co-workers (DOI: 10.1002/batt.202400604)
Space-Filling Curves for 2.5-Dimensional Meshes
Full text linkMany physical processes of the Earths atmosphere like cloud processes, convection or radiation, are strongly coupled vertically. The numerical solution of these processes motivates a higher resolution in vertical z-direction than in horizontal x- and y-direction in adaptive mesh refinement. This anisotropic mesh refinement is represented as the Cartesian product of a horizontal 2-dimensional isotropic refinement and a vertical 1-dimensional isotropic refinement. The vertical refinement depends on the horizontal refinement and
hence the term 2.5-dimensional mesh refinement is introduced. It refers to the anisotropic adaptive mesh refinement for hexahedra and prisms. A space-filling curve is used to store the elements resulting from adaptive mesh refinement. In this thesis, a space-filling curve for 2.5 dimensional adaptive mesh refinement is developed. The 2.5-dimensional space-filling curve is used to implement anisotropic 2.5-dimensional adaptive mesh refinement in the already existing isotropic tree-based approach for adaptive mesh refinement
in the open-source library t8code
Assessing import dependencies in the accelerating energy transition: A structural gravity model analysis
Full text linkThis paper examines macroeconomic issues of technological import dependence in the expansion of renewable energy generation capacity, a key concern for policymakers amid ongoing geopolitical tensions and the urgent need for a rapid energy transition. Despite the critical importance of understanding determinants in trade of clean energy technologies, previous studies have lacked empirical evidence on supply-side determinants. Using a structural gravity model, this study analyzes the relationship between technology imports and the expansion of wind and solar photovoltaic (PV) capacities. The findings reveal significant differences in countries’ development trajectories, showing that between 2000 and 2020, increases in renewable energy capacity did not substantially drive technology imports. A 100 % increase in the growth rate of wind energy capacity led to a 1.9 % increase in wind technology imports, while the same growth rate for solar PV resulted in a 6.2 % increase in PV technology imports. These findings hold even when China, the largest producer of clean energy technologies, is excluded from the dataset. Based on these results, it is recommended that policymakers continue to support renewable energy expansion, as it does not necessarily lead to higher import dependency and may offer opportunities for local industries, especially when coupled with industry-specific support measures
First Commissioning Phase Results of the Internal Calibration Concept adapted for Sentinel-1C
No full textPresentation of the first results of the adapted internal calibration concept for S-1C, gained from commissioning phase results
TerraSAR-X and TanDEM-X Mission Overview and System Status Update
No full textTerraSAR-X and its almost identical twin satellite TanDEM-X continue to acquire high resolution radar images and Digital Elevation Models with unprecedented accuracy far beyond their expected lifetime. Since launch the SAR image quality and resolution have remained constant which is owed to a very stable instrument but also to an elaborate ground segment. As a result, the bistatic mission, which was designed for 5.5 years to generate a single global Digital Elevation Model, could be extended. In the following and still ongoing TanDEM-X 4D phase, constant updates of the global dataset are acquired showing in particular the three-dimensional elevation and terrain changes over time. This is performed especially in areas where significant changes are expected as for example in mountainous areas or on glaciers. In this way, the mission has generated a unique dataset by adding change layers to the existing global Digital Elevation Model showcasing natural and man-made topography transformations over the last decade. Furthermore, various timelines could be dedicated specifically to scientific acquisitions focusing on fast changing areas such as forest or permafrost regions and enabling the application of experimental modes such as concurrent imaging.
Since both satellites are still in good condition, the ongoing missions will be continued providing continuous updates and extending this unique dataset as long as possible. In order to give an outlook on the remaining lifetime expectancy, this contribution will give a detailed overview of the current status of the systems of the satellites, the remaining onboard consumables and recent as well as upcoming operational challenges. We will present geometric calibration results using on-ground targets as well as antenna pattern measurements and baseline calibration datatakes to demonstrate the excellent radiometric stability of the system. Furthermore, since the battery is the fastest depleting resource, the focus on consumables will particularly be put on the progression of the battery ageing, the assessment of the battery capacity and the implication on the mission planning. For completeness, also the remaining fuel and the according lifetime limitation will be addressed. Additionally, recent events of external and internal nature will be discussed which temporarily affect the position determination and the synchronization of the satellites. In this context, solutions to overcome any correlated acquisitions constraints will be given.
In summary the objectives of this contribution are to validate the good condition of both satellites after 14 and 17 years in orbit as well as to demonstrate the strategies and adaptions to extend their lifetime while maintaining image quality