Parabolized stability analysis of chemically reacting boundary-layer flows in equilibrium conditions

Abstract

Stability of self-similar hypersonic flows over a flat plate in local thermodynamic equilibrium is studied by means of linear parabolized stability equations. A spectral collocation numerical method together with a finite-difference-based marching scheme are used to solve the equations, while the gas mixture and transport properties are computed with a table look-up procedure. High-temperature effects are found to destabilize the second-Mack-mode regardless of the adiabatic/isothermal wall condition considered. On the other hand, nonlocal effects show a Mach-dependence influence: stabilizing at lower Mach, while destabilizing at higher ones. Strong oscillations in the growth rate of perturbations in local thermodynamic equilibrium are found to be caused by damped supersonic modes.