Краткое описание

Supercritical fluids (SCFs) exhibit anomalous behavior in their thermo-physical properties such as diverging compressibility and vanishing thermal diffusivity on approaching the critical point. This leads to several instabilities arising in the thermal boundary layer (TBL) when these are simultaneously subjected to thermal perturbation and mechanical vibration. In the current work, 2D numerical investigation (laminar flow) of two types of instabilities, Rayleigh-vibrational and parametric instabilities are presented. Unlike the other works in literature, these are investigated using a mathematical model which calculates density directly from the mass conservation. New observations pertaining the effect of quench percentage, high acceleration on wavelength of instabilities are presented. A 3D stability plot describes the type of instability to be expected for given operating conditions in terms of amplitude, frequency and quench percentage for a given proximity to the critical point.