Enhanced inertia from lossy effective fluids using multi-scale sonic crystals

TL;DR

This paper investigates how lossy multi-scale sonic crystals can enhance the effective inertia of fluids for acoustic waves, combining theoretical modeling, numerical simulations, and experimental validation.

Contribution

It introduces a novel approach to achieve inertial enhancement using lossy sonic crystals, supported by theoretical, numerical, and experimental evidence.

Findings

Theoretical conditions for inertial enhancement are derived.

Numerical simulations confirm the theoretical predictions.

Experimental tests demonstrate enhanced inertia in fabricated structures.

Abstract

In this work, a recent theoretically predicted phenomenon of enhanced permittivity with electromagnetic waves using lossy materials is investigated for t he analogous case of mass density and acoustic waves, which represents inertial enhancement. Starting from fundamental relationships for the homogenized quasi-static effective density of a fluid host with fluid inclusions, theoretical expressions are developed for the conditions on the real and imaginary parts of the constitutive fluids to have inertial enhancement, which are verified with numerical simulations. Realizable structures are designed to demonstrate this phenomenon using multi-scale sonic crystals, which are fabricated using a 3D printer and tested in an acoustic impedance tube, yielding good agreement with the theoretical predictions and demonstrating enhanced inertia.