Homogenization of Helmholtz equation in a periodic layer to study Faraday cage-like shielding effects.

Autor: Aiyappan, S., Griso, Georges, Orlik, Julia
Předmět:
Zdroj: Complex Variables & Elliptic Equations; Apr2024, Vol. 69 Issue 4, p607-625, 19p
Abstrakt: The work is motivated by the Faraday cage effect. We consider the Helmholtz equation over a 3D domain containing a thin heterogeneous interface of thickness $ \delta \ll 1 $ δ ≪ 1. The layer has a δ-periodic structure in the in-plane directions and is cylindrical in the third direction. The periodic layer has one connected component and a collection of isolated regions. The isolated region in the thin layer represents air or liquid, and the connected component represents a solid metal grid with a δ thickness. The main issue is created by the contrast of the coefficients in the air and in the grid and that the zero-order term has a complex-valued coefficient in the connected faze while a real-valued in the complement. An asymptotic analysis with respect to $ \delta \to 0 $ δ → 0 is provided, and the limit Helmholtz problem is obtained with the Dirichlet condition on the interface. The periodic unfolding method is used to find the limit. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index