Study on Partial Coating Approach for Reducing Cavity Backscattering

Cavities are strong scattering parts for aircrafts, while coating the interior surface of cavities is a general approach for reducing cavity backscattering. In this paper, the discontinuous Galerkin (DG) method based on the self-dual integral equation (SDIE) is employed to efficiently simulate scattering from partially coated cavities. The distance sparse preconditioner (DSP) is applied to DG-SDIE for speeding up convergence instead of the conventional block-diagonal preconditioner (BDP). An efficient partial coating scheme is presented. The numerical results of straight cavity, S-shaped cavity and complex aircraft cavity demonstrate our coating scheme can achieve similar effect of reducing backscattering by using smaller coated interior surface regions. Useful conclusions about partially coating the cavity are summarized.