Rayleigh–Bénard and schwarzschild instability in a supercritical fluid

• Published in: Advances in space research Vol. 36; no. 1; pp. 11 - 16
• Main Authors: Accary, G., Raspo, I., Bontoux, P., Zappoli, B.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 2005; Elsevier
• Subjects: 3D convective instability; Engineering Sciences; Fluid mechanics; Fluids mechanics; Mechanics; Physics; Piston effect; Rayleigh–Bénard configuration; Schwarzschild criterion; Supercritical fluid; Rayleigh–Bénard configuration; Supercritical fluid; Piston effect; 3D convective instability; Schwarzschild criterion; Rayleigh-Bénard configuration
• ISSN: 0273-1177; 1879-1948
• DOI: 10.1016/j.asr.2005.02.082

Due to the density stratification, the convection onset criterion in a supercritical fluid layer heated from below includes a stabilizing effect known as the Schwarzschild criterion, which requires an adaptation of the classical low Mach number approximation. We numerically solve the mathematical model describing the motion of a supercritical fluid in the classical Rayleigh–Bénard configuration and we bring to the fore two main events: (i) the reverse transition of an unstable layer to stability without any external intervention; (ii) the convection onset according to the Schwarzschild criterion. In addition, the 3D extension of the study is briefly described.