Fast Finite-Difference Calculation of Eddy Currents in Thin Metal Sheets
Keywords:
Current density, eddy currents, finitedifference method, quasistaticsAbstract
Magnetic excitation of eddy currents in a thin metal sheet is a difficult problem that has many useful applications to scrap metal recycling. Using finitedifference approximations on both the curl and divergence of the current density, we develop a numerical algorithm that is simple to implement, quick to solve, and capable of modeling excitation from arbitrary magnetic field distributions. For the special case of a weakly-induced eddy field, the self-inductance terms can be neglected, resulting in a sparse system matrix that is easily inverted. For a strongly-induced eddy field, self-inductance must be included at the cost of a more complex, denser system matrix. The method is validated against the CST EM Studio software suite and produces nearly identical results on a thin-sheet simulation in only a tiny fraction of the time.
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References
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