Radial Absorbers for Conformal Time-Domain Methods: A Solution to Corner Problems in Mesh Truncation

A radial perfectly matched absorber is investigated for accurate computational domain truncation in con-formal time-domain methods. Using the finite-volume time-domain implementation, this radial absorber is compared with the standard unsplit perfectly matched layer (PML) and numerical reflections are computed for different test conditions. The broadband numerical results demonstrate a substantial reduction in reflection errors compared to standard PML techniques where corner reflections are dominant. For the model problem with approximately 15 points per wavelength, numerical reflection coefficients in the range of -50 to -60 dB are achieved. The presented model can be naturally adapted to other conformal time-domain methods.