Backscattering reduction in a sharply bent water wave channel

TL;DR

This paper demonstrates both theoretically and experimentally how to significantly reduce backscattering in sharply bent water wave channels using anisotropic metamaterials, enabling high transmission despite multiple turns.

Contribution

It introduces a novel application of anisotropic metamaterials to suppress backscattering in curved waveguides, applicable to water waves and other wave types with Neumann boundary conditions.

Findings

Backscattering can be effectively canceled in bent water wave channels.

Metamaterials maintain high transmission across a range of frequencies.

The approach is applicable to various wave types with Neumann boundary conditions.

Abstract

We study theoretically and experimentally how to reduce the backscattering of water waves in a channel with multiple turns. We show that it is not only possible to cancel backscattering but also to achieve a remarkable transmission in such geometries. In order to avoid the reflection that naturally arises at each turn of the waveguide, an anisotropic metamaterial made of closely-spaced thin vertical plates is used. The efficiency of the metamaterial arrangement depends only slightly on the frequency of the incident wave, as long as its wavelength is much larger than the periodicity of the array. This phenomenon is not restricted only to water wave channels but also applies to any type of waves with Neumann boundary conditions.