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Hybrid Krylov-Subspace Methods for Solving Non-Linear PDEs on Quantum Computers
No full textNumerical solvers for Partial Differential Equations (PDEs) are of great interest in various domains, e.g., in aerodynamics or for transport equations in lectrochemistry [1], and the need for fine-grained solutions of on-linear PDEs is growing. While subspace methods allow for a dimensionality reduction, non-linear PDEs require linearization schemes, such as the Carleman-linearization [2], resulting in linear systems of exponential dimensionality, operating on the limits of classical methods. Motivated by Krylov-subspace methods [3], which find approximate solutions in iteratively growing subspaces, the aim of this talk is to investigate the potential of two existing methods from quantum computing to compose a NISQ-era hybrid quantum-classical algorithm. Firstly, non-linear quantum computing (QNPUs) [4,5] and secondly Quantum Subspace Expansion (QSE) [6], both promising tools towards more scalable computations. The use of QNPUs enables linearization in a tensor-product-subspace using ancilla qubits, while offering efficient gate-based implementations. On the other hand, QSE measures high-dimensional overlaps on a quantum computer. The combination of these two methods yields the possibility of encapsulating the high-dimensional steps of linearization and subspace projection on a quantum device. As a result, only a lower-dimensional subspace problem remains to be solved on classical hardware
Influence of the ventilation concept on the comfort and the air quality - particle spreading and individual comfort zones
No full textComparison of Models and Methods for Occupant Safety Simulations in Aerospace Applications Using Virtual Anthropomorphic Test Devices
No full textEvaluierung 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)
Get PDFThe 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
Get PDFMany 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