Directional decomposition of the acoustic wave equation for fluids and metafluids in spherical geometries, with application to transformational acoustics
Artikel i vetenskaplig tidskrift, 2016
A new directional decomposition of the acoustic 3D wave equation is derived for spherically symmetric geometries, where the wave fields do not need to possess such a symmetry. This provides an alternative basis for various applications of techniques like invariant embedding and time domain Green functions in spherically symmetric geometries. Contrary to previous results on spherical wave splittings, the new decomposition is given in a very explicit form. The wave equation considered incorporates effects from radially varying compressibility and density, but also from anisotropic density, a property of certain so called metafluids. By applying the new spherical wave splitting, we show that all spherically symmetric acoustic metafluid cloaks are diffeomorphic images of a homogeneous and isotropic spherical ball of perfect fluid.
wave splitting
Mathematics
Physics
cloaking
inverse scattering
cloaking theory
telegraph equation
3 dimensions
time domain
transformational acoustics
viscoelastic media
metafluid
Författare
Peter Olsson
Chalmers, Tillämpad mekanik, Dynamik
Inverse Problems
0266-5611 (ISSN)
Vol. 32 3Ämneskategorier (SSIF 2011)
Strömningsmekanik och akustik
DOI
10.1088/0266-5611/32/3/035005