The book investigates acoustic cloaking for elliptical targets starting from the development
of a systematic approach to deal with such non-axisymmetrical shapes by adopting transformation
acoustics in elliptic coordinates and concluding with numerical and experimental validation of
a microstructured cloak in the underwater environment. The book thus comprises all the steps
from theory to practice that led to the first experimental validation of acoustic invisibility
for non-cylindrical objects whose results are presented in the last chapter. Indeed despite
Transformation Theory is now an established tool to design material distributions capable to
unlock the design of invisibility devices it is not trivial to apply it for shapes different
than the sphere and the cylinder which are thus the ones mainly addressed in the literature.
This book paves the way for exploration of other shapes demonstrating the effectiveness of a
pentamode cloak in reducing the acoustic visibility of an elliptical target and discussing
design choices that can make the implementation of the required microstructure less cumbersome
despite the lack of axial symmetry of the problem from both the numerical and manufacturing
point of views.
