Penetration of lightning electromagnetic pulses into metallic enclosures with apertures

• We propose mathematical models of LEMP structure within irregular metallic enclosures.
• There is no magnetic field within the metallic screen directly stricken by lightning.
• The hybrid simulation method we proposed earlier computationally outperforms FEM.
• Measurement error of non-uniform electric field can be calculated numerically.

Electromagnetic screening is the usual approach for protecting sensitive electronic equipment against powerful electromagnetic disturbances. Applied for this purpose real-world metallic enclosures usually contain various structural irregularities, such as apertures or chinks, which complicate the assessment of the shielding effectiveness of such electromagnetic screens even in the quasi-stationary approximation. This is mainly due to the lack of appropriate theoretical models as well as accurate and efficient practical methods for simulating temporal and spatial field distribution of lightning electromagnetic pulses (LEMP) inside metallic enclosures with apertures. In this article we introduce generic mathematical models and a novel Hybrid method based on these models, which enable simulation of spatio-temporal distribution of electromagnetic fields, induced by distant or direct lightning strikes, inside metallic enclosures with apertures. We also carry out comparative performance analysis of the Hybrid method with respect to the Finite Element Method. Finally, we assess our theoretical results by comparing them with the experimental data acquired for a dummy rocket part. Three different cases are investigated: enclosure irradiated by quasi-static electric field of LEMP, enclosure irradiated by quasi-stationary magnetic field of LEMP, and enclosure struck by a lightning directly.