Numerical study of the piston effect on the acoustic timescale

Thermal homogenization is significantly accelerated near the critical point because of the so-called piston effect. In essence, the piston effect is a thermomechanical effect. We study the momentum and energy transport in supercritical CO₂ by numerically solving the governing hydrodynamic equations. The results show explicitly the thermoacoustic nature of the process, which patently deviates from what the classical Fourier conduction model predicts.