Experimental study of influence of heavy gas injection into boundary layer on perforated model surface at Mach number 2 on its stability to controlled disturbances.

The theoretical and experimental investigation of the effect of the heavy gas (sulfur hexafluoride) blowing into the boundary layer on the hydrodynamic stability to controlled perturbations of the supersonic flat-plate boundary layer at Mach number 2 have been carried out. Artificial perturbations have been entered in the model's boundary layer by using a harmonic point glow discharge perturbation source. It is obtained that heavy gas blowing stabilizes the supersonic boundary layer. In experiments at the excitation frequency f = 14 kHz, unit Reynolds number Re₁ = 3×10⁶ m⁻¹ and streamwise coordinate x = 90 mm, it was obtained that for gas injection rate Q = 0.12 g/cm² there is a stabilization of perturbations for all spanwise wave numbers, i.e. the complete stabilization of perturbations – for all wave numbers, the spatial disturbance amplification rates are less than zero. [ABSTRACT FROM AUTHOR]