A Domain Decomposition Method for Electromagnetic Scattering Analysis of Aircraft Engine Exhaust Systems

This investigation presents the implementation of a local coupling domain decomposition method (DDM) for analyzing electromagnetic (EM) scattering characteristics of aircraft engine exhaust systems with intricate structures. The methodology involves partitioning the computational domain via an artificial reference surface at the aperture, resulting in two distinct subdomains: an exterior region encompassing the exhaust system's outer geometry, and an interior region containing the internal structures and fine geometric details. The interfacial electromagnetic coupling is maintained through rigorously imposed transmission conditions (TC) at the artificial reference surface, which establish precise continuity constraints for the electromagnetic field components. This construction generates well-conditioned matrices within their respective subdomains, resolving the numerical instability issues in traditional methods. The inherent diagonal dominance property of the resultant subdomain matrices facilitates the implementation of the flexible generalized minimal residual (FGMRES) algorithm, thereby enhancing the convergence properties of the iterative solver within the DDM framework. Consequently, this approach enables more efficient and accurate computation of the radar cross section (RCS) of complex aircraft engine exhaust system.