# Non-Closed Acoustic Cloak Enabled by Sequential-Step Linear Coordinate Transformations

## TL;DR

This paper introduces a novel non-closed acoustic cloak using sequential linear coordinate transformations, enabling the concealment of objects without enclosing them, with potential applications in airborne and underwater acoustics.

## Contribution

It presents a new design for a non-closed acoustic cloak that is independent of object geometry and material, simplifying realization and expanding application possibilities.

## Key findings

- Numerical simulations confirm effective cloaking effect.
- The cloak's design is independent of object shape and material.
- The structure has simple acoustic parameters, facilitating practical implementation.

## Abstract

Hitherto acoustic cloaking devices, which conceal objects externally, have depended on the objects' characteristics. Despite previous works, we design cloaking device placed neighbor an arbitrary object and makes it invisible without the need to make it enclosed. Applying sequential linear coordinate transformations, leads to a non-closed acoustic cloak (NCAC) with homogeneous materials that creates an open invisible region. We propose a non-closed carpet cloak to conceal objects on a reflecting plane. Numerical simulations verify the cloaking effect, which is completely independent of the geometry and material properties of the hidden object. Due to the simple acoustic constitutive parameters of presented structures, this work paves the way toward realization of non-closed acoustic devices, which could find applications in air born sound manipulation and underwater demands.

---
Source: https://tomesphere.com/paper/1904.12909