Acoustic Nonreciprocity in Coriolis Mean Flow Systems

TL;DR

This paper explores acoustic nonreciprocity using Coriolis acceleration in a fluid flow system, demonstrating how fluid velocity influences wave propagation asymmetry through numerical solutions of the governing equations.

Contribution

It introduces a novel approach to acoustic nonreciprocity by incorporating Coriolis acceleration into the wave equation, expanding beyond traditional moving medium methods.

Findings

Fluid velocity affects nonreciprocity factor significantly.

Coriolis acceleration induces asymmetric wave transmission.

Numerical solutions confirm the theoretical model.

Abstract

One way to break acoustic reciprocity is to have a moving wave propagation medium. If the acoustic wave vector and the moving fluid velocity are collinear we can use the wave vector shift caused by the fluid flow to break reciprocity. In this paper we investigated an alternative approach in which the fluid velocity enters the differential equation of the system as a cross product term with the wave vector. A circular field where the fluid velocity increases radially has a Coriolis acceleration term. In such a system, the acoustic wave enters from the central wall and exits from the perimeter wall. In this paper, we solved the differential equation numerically and investigated the effect of fluid velocity on the nonreciprocity factor.