New paper on Waveform Relaxation for Multiscale Problems

jcp Our paper on Waveform Relaxation for the Computational Homogenization of Multiscale Magnetoquasistatic Problems (Innocent Niyonzima, Christophe Geuzaine, Sebastian Schöps) has been accepted by JCP:
This paper proposes the application of the waveform relaxation method to the homogenization of multiscale magnetoquasistatic problems. In the monolithic heterogeneous multiscale method, the nonlinear macroscale problem is solved using the Newton–Raphson scheme. The resolution of many mesoscale problems per Gauss point allows to compute the homogenized constitutive law and its derivative by finite differences. In the proposed approach, the macroscale problem and the mesoscale problems are weakly coupled and solved separately using the finite element method on time intervals for several waveform relaxation iterations. The exchange of information between both problems is still carried out using the heterogeneous multiscale method. However, the partial derivatives can now be evaluated exactly by solving only one mesoscale problem per Gauss point. Continue reading →

Workshop on Order-Reduction Methods 2016

worm2016 The 3rd International Workshop on Order-Reduction Methods for Mechanics of Materials (WORM 2016) took place from Aug 29th – Wed, Aug 31st, 2016 in Bad Herrenalb, Germany. We presented recent results on domain decomposition and model order reduction in the context of Isogeometric analysis (IGA); title: Towards Reduced Order Modelling of Resonant Cavities for Particle Accelerators discretized by IGA; authors: Corno, de Falco and Schöps.

EMTS 2016 is over

emtsURSI Commission B’s International Symposium on Electromagnetic Theory (EMTS 2016) has been held from 14–18 August 2016 in Espoo, Finland. We presented in the Session of numerical time domain methods on Monday the contribution “An Application of ParaExp to Electromagnetic Wave Problems” (Melina Merkel, Innocent Niyonzima and Sebastian Schöps).

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How to build GNU Octave with Qt5 on the Mac

1503512The graphical user interface of Octave 4.0 can only be compiled with Qt4. Homebrew is dropping 4.x support and moving towards 5.x. Several Octave dependencies have already been updated (e.g. Qscintilla2, see e.g. this issue. However, the upcoming Octave 4.2 (release is scheduled for September 2016) will have full Qt5 as discussed here.

The standard installation uses the command line interface. If you need Octave with graphical user interface then this should work
brew update 
brew upgrade #to get the latest qscintilla
brew install octave --with-gui --HEAD
Update: The post has been edited on Aug 20 since the new formula is now available in homebrew’s science repository.

Talk on the simulation of electrical machines by Lars Kielhorn

logo_tailsitDr. Lars Kielhorn from TailSiT GmbH, Graz (Austria) talks on 25 Jul 2016, 16:15–17:45 (room S4|10-314) in the seminar on Computational Engineering. Abstract: Electrical machines commonly consist of moving and stationary parts, e.g., an electric motor features a rotor and a stator. If volume based numerical schemes such as the Finite Element Method (FEM) are applied the electromagnetic simulation of such devices is a challenging task since the variation of the geometrical configuration needs to be incorporated into the numerical scheme. Continue reading

Michal Maciejewski from CERN is visiting CE

CERNlogoSScadreOn Friday, July 1st Michal Maciejewski from CERN and Lodz University of Technology is visiting Computational Engineering at TU Darmstadt in the framework of the STEAM (“Simulation of Transient Effects in Accelerator Magnets”) cooperation, see e.g. this presentation. The aim of this project is the accurate prediction of quenches.

Radolsav and Zeger at EPNC 2016

EPNC-2016-logo-1-2-e1455056052945Radoslav Jankoski and Zeger Bontinck will present recent works on uncertainty quantification, i.e., Uncertainty Quantification of a PMSM With Dynamic Rotor Eccentricity and Shape Optimization of its Magnets and Stochastic Modeling of an Inhomogeneous Magnetic Reluctivity Using the Karhunen-loève Expansion and the Hierarchical Matrix Technique at the Symposium on Electromagnetic Phenomena in Nonlinear Circuits (EPNC) 2016 in Helsinki.