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



2022

4943.

Hermle, Patrick; Kreidler, Henrik
A Halmos-von Neumann theorem for actions of general groups
2022

4942.

Budde, Christian; Dobrick, Alexander; Glück, Jochen; Kunze, Markus
A monotone convergence theorem for strong Feller semigroups
2022

4941.

Ehrhardt, Matthias; Günther, Michael
A neural network enhanced weighted essentially non-oscillatory method for nonlinear degenerate parabolic equations
Physics of Fluids, 34 (2) :026604
2022
Herausgeber: AIP Publishing

4940.

Ehrhardt, Matthias; Günther, Michael
A neural network enhanced weighted essentially non-oscillatory method for nonlinear degenerate parabolic equations
Physics of Fluids, 34 (2) :026604
2022
Herausgeber: AIP Publishing

4939.

Ehrhardt, Matthias; Günther, Michael
A neural network enhanced weighted essentially non-oscillatory method for nonlinear degenerate parabolic equations
Physics of Fluids, 34 (2) :026604
2022
Herausgeber: AIP Publishing

4938.


A neural network enhanced weighted essentially non-oscillatory method for nonlinear degenerate parabolic equations
Physics of Fluids, 34 (2) :026604
2022
Herausgeber: AIP Publishing LLC

4937.

Klass, Friedemann; Gabbana, Alessandro; Bartel, Andreas
A non-reflecting boundary condition for multispeed lattice Boltzmann methods
In Ehrhardt, Matthias and Günther, Michael, Editor, Progress in Industrial Mathematics at ECMI 2021ausMathematics in Industry, Seite 447–453
In Ehrhardt, Matthias and Günther, Michael, Editor
Herausgeber: Springer Cham
2022

4936.

Klass, Friedemann; Gabbana, Alessandro; Bartel, Andreas
A non-reflecting boundary condition for multispeed lattice Boltzmann methods
In Ehrhardt, Matthias and Günther, Michael, Editor, Progress in Industrial Mathematics at ECMI 2021ausMathematics in Industry, Seite 447–453
In Ehrhardt, Matthias and Günther, Michael, Editor
Herausgeber: Springer Cham
2022

4935.

Klass, Friedemann; Gabbana, Alessandro; Bartel, Andreas
A non-reflecting boundary condition for multispeed lattice Boltzmann methods
In Ehrhardt, Matthias and Günther, Michael, Editor, Progress in Industrial Mathematics at ECMI 2021ausMathematics in Industry, Seite 447–453
In Ehrhardt, Matthias and Günther, Michael, Editor
Herausgeber: Springer Cham
2022

4934.

Klass, Friedemann; Gabbana, Alessandro; Bartel, Andreas
A non-reflecting boundary condition for multispeed lattice Boltzmann methods
In M. Ehrhardt and M. Günther, Editor, Accepted at Progress in Industrial Mathematics at ECMI 2021
Herausgeber: Springer-Verlag, Berlin
2022

ISBN: 978-3-031-11817-3

4933.

Ehrhardt, Matthias
A Nonstandard Finite Difference Scheme for a Time-Fractional Model of Zika Virus Transmission
2022

4932.

Treibert, Sarah; Brunner, Helmut; Ehrhardt, Matthias
A nonstandard finite difference scheme for the SVICDR model to predict COVID-19 dynamics
Mathematical Biosciences and Engineering, 19 (2) :1213–1238
2022
Herausgeber: AIMS Press

4931.

Treibert, Sarah; Brunner, Helmut; Ehrhardt, Matthias
A nonstandard finite difference scheme for the SVICDR model to predict COVID-19 dynamics
Mathematical Biosciences and Engineering, 19 (2) :1213–1238
2022
Herausgeber: AIMS Press

4930.

Treibert, Sarah; Brunner, Helmut; Ehrhardt, Matthias
A nonstandard finite difference scheme for the SVICDR model to predict COVID-19 dynamics
Math. Biosci. Eng, 19 (2) :1213--1238
2022

4929.

Glück, Jochen
A note on the spectrum of irreducible operators and semigroups
Proc. Amer. Math. Soc., 150 (1) :257--266
2022

4928.

Zoller, Julian; Zargaran, Amin; Braschke, Kamil; Meyer, Jörg; Janoske, Uwe; Dittler, Achim
A Novel Apparatus for Simultaneous Laser-Light-Sheet Optical Particle Counting and Video Recording in the Same Measurement Chamber at High Temperature
Sensors, 22 (4)
2022
ISSN: 1424-8220

4927.

Ehrhardt, Matthias
A physics-informed neural network to model COVID-19 infection and hospitalization scenarios
Advances in continuous and discrete models, 2022 (1) :1–27
2022
Herausgeber: Springer Science and Business Media Deutschland GmbH

4926.

Ehrhardt, Matthias
A physics-informed neural network to model COVID-19 infection and hospitalization scenarios
Advances in continuous and discrete models, 2022 (1) :1–27
2022
Herausgeber: Springer Science and Business Media Deutschland GmbH

4925.

Ehrhardt, Matthias
A physics-informed neural network to model COVID-19 infection and hospitalization scenarios
Advances in Continuous and Discrete Models, 2022 (1) :61
2022
Herausgeber: Springer International Publishing Cham

4924.

Jäschke, Jens; Ehrhardt, Matthias; Günther, Michael; Jacob, Birgit
A port-Hamiltonian formulation of coupled heat transfer
Mathematical and Computer Modelling of Dynamical Systems, 28 (1) :78–94
2022
Herausgeber: Taylor & Francis

4923.

Jäschke, Jens; Ehrhardt, Matthias; Günther, Michael; Jacob, Birgit
A port-Hamiltonian formulation of coupled heat transfer
Mathematical and Computer Modelling of Dynamical Systems, 28 (1) :78–94
2022
Herausgeber: Taylor & Francis

4922.

Jäschke, Jens; Ehrhardt, Matthias; Günther, Michael; Jacob, Birgit
A port-Hamiltonian formulation of coupled heat transfer
Mathematical and Computer Modelling of Dynamical Systems, 28 (1) :78–94
2022
Herausgeber: Taylor & Francis

4921.

Jäschke, Jens; Ehrhardt, Matthias; Günther, Michael; Jacob, Birgit
A port-Hamiltonian formulation of coupled heat transfer
Mathematical and Computer Modelling of Dynamical Systems, 28 (1) :78--94
2022
Herausgeber: Taylor & Francis

4920.

Jäschke, Jens; Ehrhardt, Matthias; Günther, Michael; Jacob, Birgit
A Port-Hamiltonian Formulation of Coupled Heat Transfer
Math. Comput. Model. Dyn. Syst., 28 (1) :78-94
2022

4919.

Jacob, Birgit; Schwenninger, Felix; Wintermayr, Jens
A refinement of Boillon's theorem on maximal regularity
Studia Math., 263 (2) :141-158
2022