Accurate method for calculating currents in wires in the vicinity of curved geometries

Abstract

International audiencePrecise methods to calculate currents are required for low frequency EMC simulations dealing with vehicles struck by lightning. The current model used resolves Maxwell’s equations combined with a Line model based on Holland’s thin wire formalism [1]. The challenge is related to the approximation of the source fields obtained with Yee’s scheme [2]. These sources are then used for the thin wire equations. In the vicinity of structures, the errors due to the staircase meshes representing surfaces corrupt the fields’ values. In order to bypass this issue, it was suggested to apply non structured meshes such as Finite Volume (FV) [3]. Difficulties are encountered when introducing thin oblique wires [4] in this last approach, in particular for the calculation of the local self inductance L, a numerical parameter required by the line model equations.In choosing a FV solver, difficulties will arise in terms of calculation resources due to the calculation procedure of the latter and to the unstructuredness of the meshes. To overcome this obstacle, a hybrid Non Structured-Structured (NST-ST) FV scheme which can also incorporate oblique Line models is proposed.To illustrate the advantage of this new approach, an open cylindrical structure with wires running along its walls will be taken into account. It will be illuminated by a plane wave and we shall compare the obtained results in terms of current and field values retrieved inside and also in the vicinity of the cables

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