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

2002

1088.


Scientific Papers-Sound Propagation Modeling-Efficient Numerical Implementation of Discrete Transparent Boundary Conditions for Parabolic Equations in Underwater Acoustics
Acustica-Stuttgart, 88 (5) :711--713
2002
Herausgeber: Stuttgart [Germany]: S. Hirzel, 1951-1995.

1087.

Tausch, Michael W.
Silicone - 1001-mal
Praxis der Naturwissenschaften - Chemie in der Schule, 51 (7) :1
2002

1086.

Tausch, Michael W.; Seesing, M.
Silicone im Chemieunterricht - Einbindung in das Thema Reaktionsmechanismen
Praxis der Naturwissenschaften - Chemie in der Schule, 51 (7) :15
2002

1085.

Klamroth, Kathrin
Single-Facility Location Problems with Barriers
Herausgeber: Springer Series in Operations Research
2002

DOI: 10.1007/b98843

1084.

Geiger, Harald; Kleffmann, Jörg; Wiesen, Peter
Smog chamber studies on the influence of diesel exhaust on photosmog formation
Atmospheric Environment, 36 (11) :1737-1747
2002
Herausgeber: Pergamon

DOI: 10.1016/S1352-2310(02)00175-9

1083.

Geiger, Harald; Kleffmann, Jörg; Wiesen, Peter
Smog chamber studies on the influence of diesel exhaust on photosmog formation
Atmospheric Environment, 36 (11) :1737-1747
2002
Herausgeber: Pergamon

DOI: 10.1016/S1352-2310(02)00175-9

1082.

Geiger, Harald; Kleffmann, Jörg; Wiesen, Peter
Smog chamber studies on the influence of diesel exhaust on photosmog formation
Atmospheric Environment, 36 (11) :1737-1747
2002
Herausgeber: Pergamon

DOI: 10.1016/S1352-2310(02)00175-9

1081.

Bunker, Philip R.; Kraemer, Wolfgang P.; Jensen, Per; Lee, Yu Chang; Lee, Yuan Pern
The matrix isolation spectrum of the CH\(_{2}\)\(^{+}\) ion
Journal of Molecular Spectroscopy, 216 (2) :419-423
2002

DOI: 10.1006/jmsp.2002.8636

1080.

Bunker, Philip R.; Kraemer, Wolfgang P.; Jensen, Per; Lee, Yu Chang; Lee, Yuan Pern
The matrix isolation spectrum of the CH\(_{2}\)\(^{+}\) ion
Journal of Molecular Spectroscopy, 216 (2) :419-423
2002

DOI: 10.1006/jmsp.2002.8636

1079.

Bunker, Philip R.; Kraemer, Wolfgang P.; Jensen, Per; Lee, Yu Chang; Lee, Yuan Pern
The matrix isolation spectrum of the CH2+ ion
Journal of Molecular Spectroscopy, 216 (2) :419-423
2002

DOI: 10.1006/jmsp.2002.8636

1078.

Jensen, Per; Odaka, Tina Erica; Kraemer, Wolfgang P.; Hirano, Tsuneo; Bunker, Philip R.
The Renner effect in triatomic molecules with application to CH\(_{2}\)\(^{+}\), MgNC and NH\(_{2}\)
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 58 (4) :763-794
2002

DOI: 10.1016/S1386-1425(01)00668-0

1077.

Jensen, Per; Odaka, Tina Erica; Kraemer, Wolfgang P.; Hirano, Tsuneo; Bunker, Philip R.
The Renner effect in triatomic molecules with application to CH\(_{2}\)\(^{+}\), MgNC and NH\(_{2}\)
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 58 (4) :763-794
2002

DOI: 10.1016/S1386-1425(01)00668-0

1076.

Jensen, Per; Odaka, Tina Erica; Kraemer, Wolfgang P.; Hirano, Tsuneo; Bunker, Philip R.
The Renner effect in triatomic molecules with application to CH2+, MgNC and NH2
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 58 (4) :763-794
2002

DOI: 10.1016/S1386-1425(01)00668-0

1075.

Drezner, Zvi; Klamroth, Kathrin; Schöbel, Anita; Wesolowsky, George O.
The Weber problem
In Drezner, Z. and Hamacher, H.W., Editor, Facility Location: Applications and Theory
Seite 1-36
Herausgeber: Springer-Verlag
2002
1-36

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1074.

Kurtenbach, Ralf; Ackermann, R.; Becker, Karl Heinz; Geyer, Andreas; Gomes, J. A. G.; L{ö}rzer, Jutta C.; Platt, Ulrich; Wiesen, Peter
Verification of the contribution of vehicular traffic to the total NMVOC emissions in Germany and the importance of the NO\(_{3}\) chemistry in the city air
Journal of Atmospheric Chemistry, 42 (1-3) :395-411
2002

DOI: 10.1023/A:1015778616796

1073.

Kurtenbach, Ralf; Ackermann, R.; Becker, Karl Heinz; Geyer, Andreas; Gomes, J. A. G.; L{ö}rzer, Jutta C.; Platt, Ulrich; Wiesen, Peter
Verification of the contribution of vehicular traffic to the total NMVOC emissions in Germany and the importance of the NO\(_{3}\) chemistry in the city air
Journal of Atmospheric Chemistry, 42 (1-3) :395-411
2002

DOI: 10.1023/A:1015778616796

1072.

Kurtenbach, Ralf; Ackermann, R.; Becker, Karl Heinz; Geyer, Andreas; Gomes, J. A. G.; Lörzer, Jutta C.; Platt, Ulrich; Wiesen, Peter
Verification of the contribution of vehicular traffic to the total NMVOC emissions in Germany and the importance of the NO3 chemistry in the city air
Journal of Atmospheric Chemistry, 42 (1-3) :395-411
2002

DOI: 10.1023/A:1015778616796

1071.

Lin, Hai; Thiel, Walter; Yurchenko, Sergey N.; Carvajal, Miguel; Jensen, Per
Vibrational energies for NH\(_{3}\) based on high level ab initio potential energy surfaces
Journal of Chemical Physics, 117 (24) :11265-11276
2002

DOI: 10.1063/1.1521762

1070.

Lin, Hai; Thiel, Walter; Yurchenko, Sergey N.; Carvajal, Miguel; Jensen, Per
Vibrational energies for NH\(_{3}\) based on high level ab initio potential energy surfaces
Journal of Chemical Physics, 117 (24) :11265-11276
2002

DOI: 10.1063/1.1521762

1069.

Lin, Hai; Thiel, Walter; Yurchenko, Sergey N.; Carvajal, Miguel; Jensen, Per
Vibrational energies for NH3 based on high level ab initio potential energy surfaces
Journal of Chemical Physics, 117 (24) :11265-11276
2002

DOI: 10.1063/1.1521762

1068.

Tausch, Michael W.; Woock, M.
Xylolmoschus - Aromatenchemie für feine Nasen
Praxis der Naturwissenschaften - Chemie in der Schule, 51 (3) :6
2002
2001--2002

1067.

Arnold, A.; Ehrhardt, M.; Rjasanow, S.
Numerik partieller Differential\-gleichungen
Vorlesungsskript, Universität Saarbrücken, WS2001/02
2001--2002
2001

1066.

[english] Korn, Silke; Tausch, Michael W.
A Laboratory Simulation for Coupled Cycles of Photosynthesis and Respiration
Journal of Chemical Education, 78 (9) :1238
2001
Herausgeber: American Chemical Society ({ACS})

DOI: 10.1021/ed078p1238

1065.

Heland, J{ö}rg; Kleffmann, Jörg; Kurtenbach, Ralf; Wiesen, Peter
A new instrument to measure gaseous nitrous acid (HONO) in the atmosphere
Environmental Science and Technology, 35 (15) :3207-3212
2001

DOI: 10.1021/es000303t

1064.

Heland, J{ö}rg; Kleffmann, Jörg; Kurtenbach, Ralf; Wiesen, Peter
A new instrument to measure gaseous nitrous acid (HONO) in the atmosphere
Environmental Science and Technology, 35 (15) :3207-3212
2001

DOI: 10.1021/es000303t