Acoustic and Electromagnetic Scattering by Large Resonant Structures

Abstract

We describe a hybrid method which will efficiently and accurately computes acoustic/electromagnetic waves scattered by a large slowly changing cavity. The cavity is constructed of a waveguide with a flanged opening at one end that couples it to free space, and another flanged opening at the other end. A schematic is shown in Figure 1. The length of this structure L ≫ λ and its walls vary on a scale length H where L ≫ H ≫ λ. This problem crudely models the air intake of a jet engine. Its size and scaling make a direct numerical approach prohibitively expensive.