Applied and Computational Mathematics (ACM)

Computational Magnetics

Many electro-technical devices such as e.g. printed circuit boards, electrical drives and antenna systems can be simulated on the basis of electrical circuits. However, the increasing frequencies and the decreasing size force designers to account for wave propagation effects, eddy-current effects, ferromagnetic saturation and hysteresis. For wave propagation effects and eddy-current effects, the results of stand-alone field simulation can be represented by an order-reduced equivalent model, which is then inserted in the overall circuit model. The representation of field-dependent nonlinearities and hysteresis effects, however, is not straightforward.

2D Simulation of a Transformer

2D Simulation of a Transformer

The coupled field and circuit simulation becomes troublesome when a large number of time steps is required. This occurs when e.g. simulating an electrical drive where the machine requires 10 periods of 50 Hz to reach nominal speed whereas the switching of the Insulated Gate Bipolar Transistors in the frequency converter switches at 20 kHz, necessitating a time steps in the order of a microsecond to be used in the simulation. Since the field model consists typically of a few million degrees of freedom, all those unknowns have to be solved in every time step. Fortunately, the relevant time constants in electrical-energy converter are in the range 50 Hz. Hence the field model does not have to be time-stepped at the same rate as the circuit model, in which fast switches are present. The use of adaptive multirate time-integration schemes can reduce the numerical complexity of the problem substantially.

Research Questions

Cooperation

Former and ongoing projects

Publications



2024

5416.

Levron, Yoash; Valadez, Alan; Weiss, George
Testing the Local Stability of a Multi-Machine Power System with Constant Power Loads
September 2024

5415.

[german] Kiesling, Elisabeth; Bohrmann-Linde, Claudia
What to do with CO2? – Eine bilinguale Schülerlaboreinheit als Beitrag zu BNE
Unterricht Chemie, 202/203 :86-91
September 2024

5414.

Fan, Jilin; Xuan, Mingjun; Zhang, Kuan; Vinokur, Rostislav; Zheng, Lifei; Göstl, Robert; Herrmann, Andreas
Accelerated Mechanophore Activation and Drug Release in Network Core-Structured Star Polymers Using High-Intensity Focused Ultrasound
Small Science, 4 (8) :2400082
August 2024

5413.

Ishaqat, Aman; Hahmann, Johannes; Lin, Cheng; Zhang, Xiaofeng; He, Chuanjiang; Rath, Wolfgang H.; Habib, Pardes; Sahnoun, Sabri E. M.; Rahimi, Khosrow; Vinokur, Rostislav; Mottaghy, Felix M.; Göstl, Robert; Bartneck, Matthias; Herrmann, Andreas
In Vivo Polymer Mechanochemistry with Polynucleotides
Advanced Materials, 36 (32) :2403752
August 2024
ISSN: 1521-4095

5412.

Fan, Jilin; Zhang, Kuan; Xuan, Mingjun; Gao, Xiang; Vinokur, Rostislav; Göstl, Robert; Zheng, Lifei; Herrmann, Andreas
High-Intensity Focused Ultrasound-Induced Disulfide Mechanophore Activation in Polymeric Nanostructures for Molecule Release
CCS Chemistry, 6 (8) :1895-1907
August 2024

5411.

Antunes, Carlos Henggeler; Fonseca, Carlos M.; Paquete, Luís; Stiglmayr, Michael
Special issue on exact and approximation methods for mixed-integer multi-objective optimization
Mathematical Methods of Operations Research
August 2024
Herausgeber: Springer Science and Business Media LLC
ISSN: 1432-5217

5410.

Tapera, Michael; Borghi, Federica; Mayer-Figge, Jan Lukas; Mittendorf, Fabia; Celik, I. E.; Gómez-Suárez, Adrián; Kirsch, S. F.
A Formal Synthesis of (+)-Hannokinol Using a Chiral Horner–Wittig Reagent
Molecules, 29 :3710
Juli 2024
Herausgeber: MDPI
ISSN: 1420-3049

5409.


Aerosol, Clouds and Trace Gases Research Infrastructure (ACTRIS): The European Research Infrastructure Supporting Atmospheric Science
Bulletin of the American Meteorological Society, 105 :E1098-E1136
Juli 2024
Herausgeber: American Meteorological Society
ISSN: 0003-0007

5408.

Klass, Friedemann; Gabbana, Alessandro; Bartel, Andreas
Characteristic boundary condition for thermal lattice Boltzmann methods
Computers & Mathematics with Applications, 157 :195-208
Juli 2024
ISSN: 0898-1221

5407.

Alcalde, Albert; Fantuzzi, Giovanni; Zuazua, Enrique
Clustering in pure-attention hardmax transformers and its role in sentiment analysis
SIAM Journal on Mathematics of Data Science, 7 (3) :1367-1393
Juni 2024

5406.

Rajkovic, Michelle; Benter, Sanna; Hammelrath, Maja; Thinius, Marco; Benter, Thorsten; Wissdorf, Walter
IDSimF: An Open-Source Framework for the Simulation of Molecular Ion Dynamics in Mass Spectrometry and Ion Mobility Spectrometry
Journal of the American Society for Mass Spectrometry
Juni 2024
Herausgeber: American Society for Mass Spectrometry. Published by the American Chemical Society. All rights reserved.
ISSN: 1044-0305

5405.

Ballaschk, Frederic; Bensberg, Kathrin; Crone, Benedikt; Kirsch, S. F.; Menz, Helge
Synthesis of the monomeric counterpart of Marinomycin A and B
Organic & Biomolecular Chemistry, 2024
Juni 2024
Herausgeber: RSC

5404.

Villena, Guillermo; Lichtenberg, Nils; Lutz, Valerie; Jessen, Wilhelm; Klein, Andreas; Kurtenbach, Ralf; Kleffmann, Jörg
TunNOx: Development and testing of a photocatalytic reactor for efficient NOx-Abatement of Road-Tunnel exhaust
Chemical Engineering Journal, 490 :151832
Juni 2024
ISSN: 13858947

5403.

Krhac, Kaja; Maschke, Bernhard; van der Schaft, Arjan
Port-Hamiltonian systems with energy and power ports
IFAC-PapersOnLine, 58(6) :280-285
Mai 2024

5402.

Heintz, Chris; Schnödewind, Lisa; Braubach, Oliver; Kersten, Hendrik; Benter, Thorsten; Wissdorf, Walter
Influence of polarity mode switching and standby times on signal stability and detection of aspirated droplet signatures in electrospray mass spectrometry
International Journal of Mass Spectrometry, 499 :117232
Mai 2024
ISSN: 13873806

5401.

[english] Wiebel, Michelle; Bensberg, Kathrin; Wende, Luca; Grandrath, Rebecca; Plitzko, Kathrin; Bohrmann-Linde, Claudia; Kirsch, Stefan F.; Schebb, Nils Helge
Efficient and simple extraction protocol for triterpenic acids from apples
Journal of Chemical Education
April 2024
Herausgeber: American Chemical Society and Division of Chemical Education, Inc.

5400.

Wiebel, Michelle; Bensberg, Kathrin; Wende, Luca; Grandrath, Rebecca; Plitzko, Kathrin; Bohrmann-Linde, Claudia; Kirsch, S. F.; Schebb, Nils Helge
Efficient and Simple Extraction Protocol for Triterpenic Acids from Apples
Journal of Chemical Education, 101 :2087-2093
April 2024
Herausgeber: ACS

5399.

Aydonat, Simay; Hergesell, Adrian H.; Seitzinger, Claire L.; Lennarz, Regina; Chang, George; Sievers, Carsten; Meisner, Jan; Vollmer, Ina; Göstl, Robert
Leveraging mechanochemistry for sustainable polymer degradation
Polymer Journal, 56 (4) :249-268
April 2024
ISSN: 1349-0540

5398.

Carslaw, Nicola; Bekö, Gabriel; Langer, Sarka; Schoemaecker, Coralie; Mihucz, Victor G.; Dudzinska, Marzenna; Wiesen, Peter; Nehr, Sascha; Huttunen, Kati; Querol, Xavier; Shaw, David
A new framework for indoor air chemistry measurements: Towards a better understanding of indoor air pollution
Indoor Environments, 1 (1) :100001
März 2024
ISSN: 29503620

5397.

Heintz, Chris; Schnödewind, Lisa; Braubach, Oliver; Kersten, Hendrik; Benter, Thorsten; Wissdorf, Walter
Observation of Large, Charged Droplet Signatures within the High-Vacuum Region of a Commercial Electrospray TOF-MS
Journal of the American Society for Mass Spectrometry, 35 (3) :508—517
März 2024
ISSN: 1044-0305, 1879-1123

5396.

[german] Tausch, Michael W.
Curriculare Innovation - Ein Imperativ für den Chemieunterricht
Band Chemie professionell unterrichten
Herausgeber: T. Palenta
Februar 2024

ISBN: 9783758478413

5395.

Rath, Wolfgang H.; Göstl, Robert; Herrmann, Andreas
Mechanochemical Activation of DNAzyme by Ultrasound
Advanced Science, 11 (8) :2306236
Februar 2024
ISSN: 2198-3844

5394.

Celik, I. E.; Mittendorf, Fabia; Gómez-Suárez, Adrián; Kirsch, S. F.
Formal synthesis of bastimolide A using a chiral Horner-Wittig reagent and a bifunctional aldehyde as key building blocks
Tetrahedron Chem, 9
Februar 2024
Herausgeber: Elsevier
ISSN: 2666-951X

5393.

Bensberg, Kathrin; Savvidis, Athanasios; Ballaschk, Frederic; Gómez-Suárez, Adrián; Kirsch, S. F.
Oxidation of Alcohols in Continuous Flow with a SolidPhase Hypervalent Iodine Catalyst
Chemistry - A European Journal, 2024 :e202304011
Februar 2024
Herausgeber: Wiley
ISSN: 0947-6539

5392.

[german] Tausch, Michael W.; Schneidewind, Jacob
Mit Licht zu grünem Wasserstoff
Chemie in unserer Zeit, 58 (1)
Februar 2024