Thomas Weiland

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— A new flexible subgridding scheme for the Finite Integration Technique is presented, which can be applied for the numerical simulation of electromagnetic phenomena in static, time and frequency domains as well as for the eigenmode computation. Numerical simulations both in the static as well as in the high frequency regime are presented to give evidence(More)
Adapted from 'Computational Fluid Dynamics', Finite Volume Time Domain (FVTD) method is becoming increasingly popular in 'Computational Electromagnetics'. The focus of this paper is on the convergence analysis of different FVTD methods on tetrahedral and hexahedral meshes. Other aspects like implementation techniques, CPU time and memory are also furnished.
The optimization of continuous parameters in electrotechnical design using electromagnetic field simulation is already standard. In this paper, we present a new sequential modelling approach for mixed-integer simulation-based optimization. We apply the method for the optimization of integer-and real-valued geometrical parameters of the coils of a(More)
The Discontinuous Galerkin (DG) method for Maxwell's equations and dedicated techniques for adaptive mesh refinement are presented. The DG method offers two refinement mechanisms: the manipulation of the local mesh step size (h-adaptation) and the adaptation of the local approximation order (p-adaptation). For both cases, a new, optimal approximation after(More)
The Yee finite-difference time domain method (FDTD) is commonly used in wake field and particle-in-cell simulations. However, in accelerator modeling the high energy particles can travel in vacuum faster than their own radiation. This effect is commonly referred to as numerical Cherenkov radiation and is a consequence of numerical grid dispersion. Several(More)
We investigate the conservation properties of the centered DO formulation for Maxwell equations. In particular, we state the problem and derive the criteria for charge conservation. It is shown that the centered scheme guarantees strict charge conservation for Cartesian discretizations with tensor product basis functions of arbitrary order. On unstructured(More)
Within the design work of FAIR, beam-stability analyses play a important role. One relevant unknown is the beam response to the kicker modules. Here we report our numerical investigations of the respective longitudinal and transverse impedances, defined by Z || (ω) = 1 q 2 d 3 xE · J * ext Z x,y (ω) = i q 2 ∆ d 3 xρ ⊥ · (E x,y ∓ vB y,x), where the(More)
This paper addresses the nonlinear elliptic curl–curl equation with uncertainties in the material law. It is frequently employed in the numerical evaluation of magnetostatic fields, where the uncertainty is ascribed to the so–called B–H curve. A truncated Karhunen – Lò eve approximation of the stochastic B – H curve is presented and analyzed with regard to(More)