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



2005

1454.

Yurchenko, Sergey N.; Bunker, Philip R.; Jensen, Per
Coulomb explosion imaging: the CH3+ and H3O+ molecules
Journal of Molecular Structure, 742 (1-3) :43-48
2005
Herausgeber: Elsevier

1453.

Kleffmann, Jörg; Gavriloaiei, Traian; Hofzumahaus, Andreas; Holland, Frank; Koppmann, Ralf; Rupp, Lutz; Schlosser, Eric; Siese, Manfred; Wahner, Andreas
Daytime formation of nitrous acid: A major source of OH radicals in a forest
Geophysical Research Letters, 32 (5) :1-4
2005
Herausgeber: John Wiley & Sons, Ltd

1452.

Kleffmann, Jörg; Gavriloaiei, Traian; Hofzumahaus, Andreas; Holland, Frank; Koppmann, Ralf; Rupp, Lutz; Schlosser, Eric; Siese, Manfred; Wahner, Andreas
Daytime formation of nitrous acid: A major source of OH radicals in a forest
Geophysical Research Letters, 32 (5) :1-4
2005
Herausgeber: John Wiley \& Sons, Ltd

1451.

Kleffmann, Jörg; Gavriloaiei, Traian; Hofzumahaus, Andreas; Holland, Frank; Koppmann, Ralf; Rupp, Lutz; Schlosser, Eric; Siese, Manfred; Wahner, Andreas
Daytime formation of nitrous acid: A major source of OH radicals in a forest
Geophysical Research Letters, 32 (5) :1-4
2005
Herausgeber: John Wiley \& Sons, Ltd

1450.

Kirsch, Stefan F.; Bach, Thorsten
Diastereoselective Reactions at Enantiomerically Pure, Sterically Congested Cyclohexanes as an Entry to Wailupemycins A and B: Total Synthesis of (+)-Wailupemycin B
Chemistry - A European Journal, 11 (23) :7007–7023
2005
ISSN: 0947-6539, 1521-3765

1449.

Kirsch, Stefan F.; Bach, Thorsten
Diastereoselective Reactions at Enantiomerically Pure, Sterically Congested Cyclohexanes as an Entry to Wailupemycins A and B: Total Synthesis of (+)-Wailupemycin B
Chemistry - A European Journal, 11 (23) :7007–7023
2005
ISSN: 0947-6539, 1521-3765

1448.

Yurchenko, Sergei N.; Carvajal, Miguel; Lin, Hai; Zheng, Jingjing; Thiel, Walter; Jensen, Per
Dipole moment and rovibrational intensities in the electronic ground state of NH\(_{3}\): Bridging the gap between ab initio theory and spectroscopic experiment
The Journal of Chemical Physics, 122 (10) :104317
2005

1447.

Yurchenko, Sergei N.; Carvajal, Miguel; Lin, Hai; Zheng, Jingjing; Thiel, Walter; Jensen, Per
Dipole moment and rovibrational intensities in the electronic ground state of NH\(_{3}\): Bridging the gap between ab initio theory and spectroscopic experiment
The Journal of Chemical Physics, 122 (10) :104317
2005

1446.

Yurchenko, Sergei N.; Carvajal, Miguel; Lin, Hai; Zheng, Jingjing; Thiel, Walter; Jensen, Per
Dipole moment and rovibrational intensities in the electronic ground state of NH3: Bridging the gap between ab initio theory and spectroscopic experiment
The Journal of Chemical Physics, 122 (10) :104317
2005

1445.

Ehrhardt, Matthias
Discrete transparent boundary conditions for transient kp-Schrödinger equations with application to quantum heterostructures
ZAMM-Zeitschrift fur Angewandte Mathematik und Mechanik, 85 (11) :793–805
2005
Herausgeber: WILEY-VCH Verlag

1444.

Ehrhardt, Matthias
Discrete transparent boundary conditions for transient kp-Schrödinger equations with application to quantum heterostructures
ZAMM-Journal of Applied Mathematics and Mechanics/Zeitschrift für Angewandte Mathematik und Mechanik: Applied Mathematics and Mechanics, 85 (11) :793--805
2005
Herausgeber: WILEY-VCH Verlag Berlin

1443.

Ehrhardt, Matthias
Discrete transparent boundary conditions for wide angle parabolic equations for non-vanishing starting fields
Preprint, Research Center Matheon :1–15
2005
Herausgeber: Technische Universität Berlin

1442.

Ehrhardt, Matthias
Discrete Transparent Boundary Conditions for Wide Angle Parabolic Equations for non-vanishing starting fields
2005

1441.

Sevat, M. F.; Houben, S. H. M. J.; Maten, E. J. W.
DRK Methods for Time-Domain Oscillator Simulation
, Progress in Industrial Mathematics at {ECMI} 2004, Eindhoven Band 8 aus Mathematics in Industry
Seite 194-198
Herausgeber: Springer Berlin Heidelberg
2005
194-198

1440.

Ehrhardt, Matthias
Finite difference schemes on unbounded domains
In R. E. Mickens, Editor, Advances in the Applications of Nonstandard Finite Difference Schemes Band 2
Seite 343--384
Herausgeber: World Scientific
2005
343--384

1439.

Ehrhardt, Matthias
Finite difference schemes on unbounded domains
Seite 343–384
Herausgeber: World Scientific Publishing
2005
343–384

1438.

Arsene, C.; Barnes, Ian; Becker, Karl Heinz; Benter, Thorsten
Gas-phase reaction of Cl with dimethyl sulfide: Temperature and oxygen partial pressure dependence of the rate coefficient
International Journal of Chemical Kinetics, 37 (2) :66-73
2005
Herausgeber: John Wiley \& Sons, Ltd

1437.

Arsene, C.; Barnes, Ian; Becker, Karl Heinz; Benter, Thorsten
Gas-phase reaction of Cl with dimethyl sulfide: Temperature and oxygen partial pressure dependence of the rate coefficient
International Journal of Chemical Kinetics, 37 (2) :66-73
2005
Herausgeber: John Wiley \& Sons, Ltd

1436.

Arsene, C.; Barnes, Ian; Becker, Karl Heinz; Benter, Thorsten
Gas-phase reaction of Cl with dimethyl sulfide: Temperature and oxygen partial pressure dependence of the rate coefficient
International Journal of Chemical Kinetics, 37 (2) :66-73
2005
Herausgeber: John Wiley & Sons, Ltd

1435.

Suhre, Michael H.; Reif, Michael; Kirsch, Stefan F.
Gold(I)-Catalyzed Synthesis of Highly Substituted Furans
Organic Letters, 7 (18) :3925–3927
2005
ISSN: 1523-7060

1434.

Suhre, Michael H.; Reif, Michael; Kirsch, Stefan F.
Gold(I)-Catalyzed Synthesis of Highly Substituted Furans
Organic Letters, 7 (18) :3925–3927
2005
ISSN: 1523-7060

1433.


Handbook of Numerical Analysis Vol. XIII. Special Volume: Numerical Methods in Electromagnetics
In Schilders, W. H. A. and ter Maten, E. J. W., Editor
Herausgeber: Elsevier Science
2005

ISBN: 0444513752

1432.

Kleffmann, Jörg; Wiesen, Peter
Heterogeneous conversion of NO\(_{2}\) and NO on HNO\(_{3}\) treated soot surfaces: atmospheric implications
Atmospheric Chemistry and Physics, 5 (1) :77-83
2005

1431.

Kleffmann, Jörg; Wiesen, Peter
Heterogeneous conversion of NO\(_{2}\) and NO on HNO\(_{3}\) treated soot surfaces: atmospheric implications
Atmospheric Chemistry and Physics, 5 (1) :77-83
2005

1430.

Kleffmann, Jörg; Wiesen, Peter
Heterogeneous conversion of NO2 and NO on HNO3 treated soot surfaces: atmospheric implications
Atmospheric Chemistry and Physics, 5 (1) :77-83
2005