Acoustic Eaton lens array and its fluid application

TL;DR

This paper proposes a theoretical design for an acoustic Eaton lens array made of expandable rubber balloons to serve as a removable tsunami barrier, reducing wave pressure and reflection.

Contribution

It introduces a novel fluid-based, expandable lens array concept for tsunami protection, combining acoustic lens principles with practical deployment and reusability.

Findings

Numerical simulation demonstrates wave pressure reduction.

Design enables rapid deployment within hours.

Reusability of the lens array after tsunami events.

Abstract

A principle of an acoustic Eaton Lens array and its application as a removable tsunami wall is proposed theoretically. The lenses are made of expandable rubber pillars or balloons and create a stop-band by the rotating the incoming tsunami wave and reduce the pressure by canceling each other. The diameter of each lens is larger than the wavelength of the tsunami near the coast, that is, order of a kilometer. The impedance matching on the border of the lenses results in little reflection. Before a tsunami, the balloons are buried underground in shallow water near the coast in folded or rounded form. Upon sounding of the tsunami alarm, water and air are pumped into the pillars, which expand and erect the wall above the sea level within a few hours. After the tsunami, the water and air are released from the pillars, which are then buried underground for reuse. Electricity is used to power the entire process. A numerical simulation with a linear tsunami model was carried out.