Wave scattering calculation for particles of arbitrary shape based on scale separation in the Green's function

The paper presents a method for the simulation of acoustic and electromagnetic scattering from arbitrary-shaped particles. The method is based on an analytical scale separation of the scatterer and far-field regions for the Green's functions. The scattered field in the far zone is found through a specific volume integral of the scattered field inside the scatterer volume only. The main idea of the developed numerical procedure lies in the approach to the near-to-far-field transformation, while a required field inside a scatterer volume can be evaluated by any available method, e.g., the finite-element method, which is used in the work. A comparison of the numerical results obtained with the developed method and with the Mie and $T$-matrix solutions shows that a good and controllable accuracy can be achieved for both resonant metallic and dielectric scatterers.