Thermo-acoustic wave propagation and reflection near the liquid-gas critical point

TL;DR

This paper investigates thermo-acoustic wave behavior near the liquid-gas critical point, combining numerical simulations with experimental data to reveal new reflection patterns influenced by diverging bulk viscosity.

Contribution

It introduces a numerical model that accurately reproduces experimental thermo-acoustic responses near the critical point, highlighting the role of diverging bulk viscosity in wave reflection.

Findings

Numerical results match experimental data well.

Reflection patterns are significantly affected by bulk viscosity divergence.

New features of wave reflection near the critical point are identified.

Abstract

We study the thermo-acoustic wave propagation and reflection near the liquid-gas critical point. Specifically, we perform a numerical investigation of the acoustic responses in a near-critical fluid to thermal perturbations based on the same setup of a recent ultrasensitive interferometry measurement in CO2 [Y. Miura et al. Phys. Rev. E 74, 010101(R) (2006)]. The numerical results agree well with the experimental data. New features regarding the reflection pattern of thermo-acoustic waves near the critical point under pulse perturbations are revealed by the proper inclusion of the critically diverging bulk viscosity.