References of "Geuzaine, Christophe"
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See detailOptimizing Perfectly Matched Layers in Discrete Contexts
Modave, Axel ULg; Delhez, Eric ULg; Geuzaine, Christophe ULg

in International Journal for Numerical Methods in Engineering (2014), 99(6), 410437

Perfectly Matched Layers (PMLs) are widely used for the numerical simulation of wave-like problems defined on large or infinite spatial domains. However, for both the time-dependent and the time-harmonic ... [more ▼]

Perfectly Matched Layers (PMLs) are widely used for the numerical simulation of wave-like problems defined on large or infinite spatial domains. However, for both the time-dependent and the time-harmonic cases, their performance critically depends on the so-called absorption function. This paper deals with the choice of this function when classical numerical methods are used (based on finite differences, finite volumes, continuous finite elements and discontinuous finite elements). After reviewing the properties of the PMLs at the continuous level, we analyse how they are altered by the different spatial discretizations. In the light of these results, different shapes of absorption function are optimized and compared by means of both one- and two-dimensional representative time-dependent cases. This study highlights the advantages of the so-called shifted hyperbolic function, which is efficient in all cases and does not require the tuning of a free parameter, by contrast with the widely used polynomial functions. [less ▲]

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See detailA relaxation scheme to combine Phasor-Mode and Electromagnetic Transients Simulations
Plumier, Frédéric ULg; Aristidou, Petros ULg; Geuzaine, Christophe ULg et al

in Proceedings of the 18th Power System Computation Conference (2014, August)

This paper deals with a new scheme for coupling phasor-mode and electromagnetic transients simulations. In each simulation, an iteratively updated linear equivalent is used to represent the effect of the ... [more ▼]

This paper deals with a new scheme for coupling phasor-mode and electromagnetic transients simulations. In each simulation, an iteratively updated linear equivalent is used to represent the effect of the subsystem treated by the other simulation. Time interpolation and phasor extraction methods adapted to this scheme are presented and compared to existing methods. Finally, simulation results obtained with a 74-bus test system are reported. [less ▲]

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See detailGEOMETRICAL VALIDITY OF HIGH-ORDER PYRAMIDAL FINITE ELEMENTS
Johnen, Amaury ULg; Geuzaine, Christophe ULg

Conference (2014, July 24)

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See detailOn the convergence of relaxation schemes to couple phasor-mode and electromagnetic transients simulations
Plumier, Frédéric ULg; Geuzaine, Christophe ULg; Van Cutsem, Thierry ULg

in Proceedings of the IEEE PES General Meeting (2014, July)

Hybrid simulations combining phasor-mode and electromagnetic transients models aim at taking advantage of computational speed of the former and accuracy of the latter. For simulation accuracy, a ... [more ▼]

Hybrid simulations combining phasor-mode and electromagnetic transients models aim at taking advantage of computational speed of the former and accuracy of the latter. For simulation accuracy, a relaxation process is used, which consists of iterating between both models. The convergence properties of this relaxation process are investigated. The speed of convergence is assessed when the variables exchanged at the interface between both models are respectively pure voltage/current sources, Norton/Thévenin equivalents, or a combination of them. Iteratively updated Norton/Thévenin equivalents are shown to drastically reduce the number of relaxation iterations. [less ▲]

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See detailDouble Sweep Preconditioners for propagation problems solved by Optimized Schwarz Methods
Vion, Alexandre ULg; Geuzaine, Christophe ULg

in Proceedings of the 6th International Conference on Advanced COmputational Methods in ENgineering, ACOMEN 2014 (2014, June)

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See detailAnalysis of transient scattering problems using a discontinuous Galerkin method: application to the shielding effectiveness of enclosures with heterogeneous walls
Boubekeur, Mohamed; Kameni, Abelin; Pichon, Lionel et al

in International Journal of Numerical Modelling: Electronic Networks, Devices and Fields (2014), 27(3), 626-635

In this paper, different formulations of Maxwell equations are combined for computing the shielding effectiveness of enclosures made from heterogeneous periodic materials. The validity of the homogenized ... [more ▼]

In this paper, different formulations of Maxwell equations are combined for computing the shielding effectiveness of enclosures made from heterogeneous periodic materials. The validity of the homogenized parameters given by Maxwell-Garnett rules in the frequency domain are tested in the time domain using a nodal discontinuous Galerkin method, which uses an interface condition based on analytical solution in the frequency domain to replace a conductive sheet. This interface condition allows to avoid meshing the thin sheet, thus reducing the computational cost. Results of scattering by composite enclosures are presented in the frequency domain thanks to a Fast Fourier Transform. [less ▲]

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See detailOptimized Waveform Relaxation Methods for Modeling Electromagnetic Field-Circuit Problems
Nshimiyimana, Jean de Dieu ULg; Plumier, Frédéric ULg; Dular, Patrick ULg et al

in Proceedings of Sixteenth Biennal IEEE Conference on Electromagnetic Field Computation (2014, April)

The convergence of classical and optimized waveform relaxation methods is compared for the simulation of field-circuit problems, where a finite element solver is used for the solution of the field problem ... [more ▼]

The convergence of classical and optimized waveform relaxation methods is compared for the simulation of field-circuit problems, where a finite element solver is used for the solution of the field problem and a circuit simulator is used for the electronic circuit. [less ▲]

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See detailNonlinear Computational Homogenization Method for the Evaluation of Eddy Currents in Soft Magnetic Composites
Niyonzima, Innocent ULg; Sabariego, Ruth Vazquez; Dular, Patrick ULg et al

in IEEE Transactions on Magnetics (2014), 50(02),

In this paper, a heterogeneous multiscale method technique is applied to model the behavior of electromagnetic fields in soft magnetic composites (SMC). Two problems are derived from the two-scale ... [more ▼]

In this paper, a heterogeneous multiscale method technique is applied to model the behavior of electromagnetic fields in soft magnetic composites (SMC). Two problems are derived from the two-scale homogenization theory: a macroscale problem that captures the slow variations of the overall solution, and many mesoscale problems that allow determining the constitutive laws at the macroscale. As application, an SMC core is considered. [less ▲]

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See detailEfficient finite element assembly of high order whitney forms
Marsic, Nicolas ULg; Geuzaine, Christophe ULg

in IET Conference Proceedings (2014)

This paper presents an efficient method for the finite element assembly of high order Whitney elements. We start by reviewing the classical assembly technique and by highlighting the most time consuming ... [more ▼]

This paper presents an efficient method for the finite element assembly of high order Whitney elements. We start by reviewing the classical assembly technique and by highlighting the most time consuming part. Then, we show how this classical approach can be reformulated into a computationally efficient matrix - matrix product. We also address the problem of the basis orientation by considering more than one reference space. We conclude by presenting numerical results on a wave guide problem. [less ▲]

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See detailSpecial Issue: The 9th International Symposium on Electric and Magnetic Fields (EMF 2013)
Dupre, Luc; Geuzaine, Christophe ULg

Book published by Wiley & Sons (2014)

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See detailA dynamical energy-based hysteresis model for iron loss calculation in laminated cores
Steentjes, S.; Henrotte, F.; Geuzaine, Christophe ULg et al

in International Journal of Numerical Modelling (2014), 27(3), 433-443

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See detailIron loss calculation in steel laminations at high frequencies
Henrotte, François; Steentjes, Simon; Hameyer, Kay et al

in IEEE Transactions on Magnetics (2014), 50(2), 333-336

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See detailA 3-D Semi-Implicit Method for Computing the Current Density in Bulk Superconductors
Kameni, Abelin; Boubekeur, Mohamed; Alloui, Lotfi et al

in IEEE Transactions on Magnetics (2014), 50(2), 377--380

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See detailA frontal approach to hex-dominant mesh generation
Baudouin, Tristan Carrier; Remacle, Jean-François; Marchandise, Emilie et al

in Advanced Modeling and Simulation in Engineering Sciences (2014), 1(1), 1-30

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See detailShape Optimization of Interior Permanent Magnet Motor for Torque Ripple Reduction
Kuci, Erin ULg; Geuzaine, Christophe ULg; Dular, Patrick ULg et al

in Proceedings of The 4th International Conference on Engineering Optimization: Lisbon (Portugal), 8-11 September 2014 (2014)

The objective of the paper is to present an open source environment to perform the design, simulation (Gmsh, GetDP) and optimization (OpenOpt) of electrical machines. The design of the permanent magnets ... [more ▼]

The objective of the paper is to present an open source environment to perform the design, simulation (Gmsh, GetDP) and optimization (OpenOpt) of electrical machines. The design of the permanent magnets of a v-shaped interior permanent magnet machine is then considered. The later is modeled using the finite element method with a formulation based on the magnetic vector potential. Optimization is based on mathematical programming approach. A semi-analytical sensitivity analysis is compared with the finite difference. Thanks to this approach, the design time is much shorter than that required by an approach of trial and error used by industry. The reduction of the torque ripple is about 70 \% with respect to the original design. [less ▲]

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See detailDouble sweep preconditioner for optimized Schwarz methods applied to the Helmholtz problem
Vion, Alexandre ULg; Geuzaine, Christophe ULg

in Journal of Computational Physics (2014), 266

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See detailEvaluation of shielding effectiveness of composite wall with a time domain discontinuous Galerkin method
Kameni, Abelin; Modave, Axel ULg; Boubekeur, Mohamed et al

in European Physical Journal : Applied physics (2013), 64(2), 24508

This article presents a Time Domain Discontinuous Galerkin method applied for solving the conservative form of Maxwell equations and computing the radiated fields in electromagnetic compatibility problems ... [more ▼]

This article presents a Time Domain Discontinuous Galerkin method applied for solving the conservative form of Maxwell equations and computing the radiated fields in electromagnetic compatibility problems. The results obtained in homogenous media for the transverse magnetic waves are validated in two cases. We compare our solution to an analytical solution of Maxwell’s equations based on characteristic method. Our results on shielding effectiveness of a conducting wall are same as those obtained from analytical expression in frequency domain. The propagation in heterogeneous medium is explored. The shielding effectiveness of a composite wall partially filled by circular conductives inclusions is computed. The proposed results are in conformity with the classical predictive homogenizations rules. [less ▲]

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See detailAn optimum PML for scattering problems in the time domain
Modave, Axel ULg; Kameni, Abelin; Lambrechts, Jonathan et al

in European Physical Journal : Applied physics (2013), 64(2), 24502

In electromagnetic compatibility, scattering problems are defined in an infinite spatial domain, while numerical techniques such as finite element methods require a computational domain that is bounded ... [more ▼]

In electromagnetic compatibility, scattering problems are defined in an infinite spatial domain, while numerical techniques such as finite element methods require a computational domain that is bounded. The perfectly matched layer (PML) is widely used to simulate the truncation of the computational domain. However, its performance depends critically on an absorption function. This function is generally tuned by using case-dependent optimization procedures. In this paper, we will present some efficient functions that overcome any tuning. They will be compared using a realistic scattering benchmark solved with the Discontinuous Galerkin method. [less ▲]

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