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



2018

3942.

Frommer, Andreas; Schimmel, Claudia; Schweitzer, Marcel
Bounds for the decay of the entries in inverses and Cauchy-Stieltjes functions of certain sparse, normal matrices
Numer. Linear Algebra Appl., 25 (4) :e2131, 17
2018

3941.

Frommer, Andreas; Schimmel, Claudia; Schweitzer, Marcel
Bounds for the decay of the entries in inverses and Cauchy-Stieltjes functions of certain sparse, normal matrices
Numer. Linear Algebra Appl., 25 (4) :e2131, 17
2018

3940.

Frommer, Andreas; Schimmel, Claudia; Schweitzer, Marcel
Bounds for the decay of the entries in inverses and Cauchy-Stieltjes functions of certain sparse, normal matrices
Numer. Linear Algebra Appl., 25 (4) :e2131, 17
2018

3939.

Heilmann, Margareta; Raşa, Ioan
C0-semigroups associated with uniquely ergodic Kantorovich modifications of operators
Positivity, 22 :829-835
2018

3938.

[german] Spinnen, Sebastian; Tausch, Michael W.
Chem4Digit - Chemie für digitale Logik
CHEMKON, 25 (2) :69--73
2018
Herausgeber: Wiley

3937.

Meuter, Nico
Chemie 2 Berlin/Brandenburg, Gefährdungsbeurteilungen 2
In Claudia Bohrmann-Linde and Simone Krees and I. Siehr, Editor
Herausgeber: C. C. Buchner
2018

3936.

[german] Meuter, Nico
Chemie Baden-Württemberg LB 1 mit GFB
In Claudia Bohrmann-Linde and Jochen Krüger and Klaus Schneiderhan, Editor
Kapitel Gef{\~A}¤hrdungsbeurteilungen
Herausgeber: C. C. Buchner
2018

3935.

Bohrmann-Linde, Claudia; Kleefeldt, Simon
Chemische Reaktionen mit der Wärmebildkamera betrachtet
Nachrichten aus der Chemie, 66 (12) :1182-1185
2018
Herausgeber: Wiley

3934.

Kleffmann, Jörg
Comment on ''Wavelength-Resolved Photon Fluxes of Indoor Light Sources: Implications for HO\(_{x}\) Production''
Environmental Science \& Technology, 52 (18) :11964-11965
2018

3933.

Kleffmann, Jörg
Comment on ''Wavelength-Resolved Photon Fluxes of Indoor Light Sources: Implications for HO\(_{x}\) Production''
Environmental Science \& Technology, 52 (18) :11964-11965
2018

3932.

Kleffmann, Jörg
Comment on "Wavelength-Resolved Photon Fluxes of Indoor Light Sources: Implications for HOx Production"
Environmental Science & Technology, 52 (18) :11964-11965
2018

3931.

Kreidler, Henrik
Compact operator semigroups applied to dynamical systems
Semigroup Forum, 97 (3) :523--547
2018

3930.

Heilmann, Margareta; Nasaireh, Fadel; Raşa, Ioan
Complements to Voronovskaja's formula
Mathematics and Computing - ICMC 2018,Band Springer Proceedings in Mathematics and Computing, Seite 127-134
ICMC 2018
Varanasi, India
January 9-11, 2018
In Debdas Ghosh, Debasis Giri, Ram N. Mohapatra, Kouichi Sakurai, Ekrem Savas and Tanmoy Som, Editor
Herausgeber: Springer
2018

3929.

Hirano, Tsuneo; Nagashima, Umpei; Jensen, Per
Computational molecular spectroscopy of X\verb=~=\(^{2}\)\(\Pi\) NCS: Electronic properties and ro-vibrationally averaged structure
Journal of Molecular Spectroscopy, 346 :4-12
2018
Herausgeber: Academic Press

3928.

Hirano, Tsuneo; Nagashima, Umpei; Jensen, Per
Computational molecular spectroscopy of X\verb=~=\(^{2}\)\(\Pi\) NCS: Electronic properties and ro-vibrationally averaged structure
Journal of Molecular Spectroscopy, 346 :4-12
2018
Herausgeber: Academic Press

3927.

Hirano, Tsuneo; Nagashima, Umpei; Jensen, Per
Computational molecular spectroscopy of X~2Π NCS: Electronic properties and ro-vibrationally averaged structure
Journal of Molecular Spectroscopy, 346 :4-12
2018
Herausgeber: Academic Press

3926.

Freund, Jens; Galleguillos Kempf, Sarah C.; Jensen, Per; Nagashima, Umpei; Hirano, Tsuneo
Computational spectroscopy of NCS in the Renner-degenerate electronic state X\verb=~=\(^{2}\)\(\Pi\)
Journal of Molecular Spectroscopy, 345 :31-38
2018
Herausgeber: Academic Press

3925.

Freund, Jens; Galleguillos Kempf, Sarah C.; Jensen, Per; Nagashima, Umpei; Hirano, Tsuneo
Computational spectroscopy of NCS in the Renner-degenerate electronic state X\verb=~=\(^{2}\)\(\Pi\)
Journal of Molecular Spectroscopy, 345 :31-38
2018
Herausgeber: Academic Press

3924.

Freund, Jens; Galleguillos Kempf, Sarah C.; Jensen, Per; Nagashima, Umpei; Hirano, Tsuneo
Computational spectroscopy of NCS in the Renner-degenerate electronic state X~2Π
Journal of Molecular Spectroscopy, 345 :31-38
2018
Herausgeber: Academic Press

3923.

Metzger, Jutta; Nied, Manuela; Corsmeier, Ulrich; Kleffmann, Jörg; Kottmeier, Christoph
Dead Sea evaporation by eddy covariance measurements vs. aerodynamic, energy budget, Priestley-Taylor, and Penman estimates
Hydrology and Earth System Sciences, 22 (2) :1135-1155
2018

3922.

Metzger, Jutta; Nied, Manuela; Corsmeier, Ulrich; Kleffmann, Jörg; Kottmeier, Christoph
Dead Sea evaporation by eddy covariance measurements vs. aerodynamic, energy budget, Priestley-Taylor, and Penman estimates
Hydrology and Earth System Sciences, 22 (2) :1135-1155
2018

3921.

Metzger, Jutta; Nied, Manuela; Corsmeier, Ulrich; Kleffmann, Jörg; Kottmeier, Christoph
Dead Sea evaporation by eddy covariance measurements vs. aerodynamic, energy budget, Priestley-Taylor, and Penman estimates
Hydrology and Earth System Sciences, 22 (2) :1135-1155
2018

3920.

Gausling, Kai; Bartel, Andreas
Density Estimation Techniques in Cosimulation Using Spectral- and Kernel Methods
In Langer, U. and Amrhein, W. and Zulehner, W., Editor, Scientific Computing in Electrical Engineering: SCEE 2016, St. Wolfgang, Austria, October 2016Band28, Seite 81--89
Springer International Publishing
In Langer, U. and Amrhein, W. and Zulehner, W., Editor
Herausgeber: Springer
2018

3919.

Gausling, Kai; Bartel, Andreas
Density estimation techniques in cosimulation using Spectral-and Kernel methods
In Langer, Ulrich and Amrhein, Wolfgang and Zulehner, Walter, Editor, Scientific Computing in Electrical Engineering: SCEE 2016, St. Wolfgang, Austria, October 2016ausMathematics in Industry, Seite 81–89
In Langer, Ulrich and Amrhein, Wolfgang and Zulehner, Walter, Editor
Herausgeber: Springer Cham
2018

3918.

Calore, Enrico; Gabbana, Alessandro
Design and optimizations of lattice Boltzmann methods for massively parallel GPU-based blusters
Seite 54–114
Herausgeber: IGI Global
2018
54–114