Thermoacoustic effects in supercritical fluids near the critical point: Resonance, piston effect, and acoustic emission and reflection

Abstract

We present a general theory of thermoacoustic phenomena in supercritical fluids near the critical point in a one-dimensional cell. We take into account the effects of the heat conduction in the boundary walls and the bulk viscosity near the critical point. We introduce a coefficient $Z(\omega )$ characterizing reflection of sound with frequency $\omega$ at the boundary. As applications, we examine the acoustic eigenmodes in the cell, the response to time-dependent perturbations, sound emission and reflection at the boundary. Resonance and rapid adiabatic changes are noteworthy. In these processes, the role of the thermal diffusion layers is enhanced near the critical point because of the strong critical divergence of the thermal expansion.

15 pages, 7 figures

References in corpus (1)

• High-speed observation of the piston effect near the gas-liquid critical point

Cited by in corpus (2)

• Droplet evaporation in one-component fluids: Dynamic van der Waals theory
• Thermo-acoustic wave propagation and reflection near the liquid-gas critical point