Scattering pattern of acoustic cloak in compressible non-uniform mean flow

Abstract

For the last decade, research of acoustic cloak has been attracting many researchers based on the previous works of optical cloak. However, because the sound and light have different physical properties, there are clear limitations to research the acoustic cloak based on the analogy between Optics and Acoustics. But most of the previous approaches on acoustic cloak have assumed the stationary state of medium. Thus, the analysis of the acoustic cloak in moving medium is needed for an adequate application of the cloak to practical situation. In this study, we propose a theoretical framework to analyze the acoustic cloak impinged by sound wave in non-uniform and compressible flow field, which has spatially-varying flow velocity and density of background medium. In addition, the numerical method (FEM) is applied to illustrate and analyze the scattering pattern of sound around the acoustic cloak. Ultimately, we expect that the present study will provide an idea to design a new acoustic cloak.