Temporal Instability of a Transcritical Shear Layer

摘要

A linear stability analysis of a shear layer formed by injecting a cryogenic jet into a supercritical environment was carried out. The stability solution of a transcritical shear layer was found using a normal mode approach. The modified Soave-Redlich-Kwong equation of state was used to include the real gas effects. By examining the temporal instability characteristics of the shear layers under different thermodynamic parameters, it was concluded that the instability behavior of the transcritical shear layers was determined mainly by the interval between the inflections of the velocity and density profiles. The density stratification (i.e., the great density gradient at the critical point) and the density ratio between the freestreams dominated the supercritical and subcritical shear layers, respectively. The total effects, determined by coupling density stratification, density ratio, and interval between the inflections of the velocity and density profiles, were quite distinct for different temperature range and the detailed path mat the temperature distributed.