Investigating Low-Rank Approximations for the Finite Element-Boundary Integral Method

This paper explores acceleration of the finite element-boundary integral hybrid method using the adaptive cross approximation. Our code implementing the hybrid method in Python based on open source packages is briefly presented. A simple one-level version of the adaptive cross approximation is described and it is used to accelerate the boundary integral matrices. We present results for scattering against a dielectric sphere with a comparison to analytical results for verification. We also present results for scattering against cylinders with varying length, where cylinders were selected as a simplification of wind turbine blades. Comparisons between a full matrix assembly and the acceleration method show that significant compression can be achieved, even with a simple acceleration scheme. We also present the monostatic radar cross-section for the largest cylinder computed for multiple angles of incidence.