Experimental investigation of the stability of a supersonic boundary layer on a plate with blunting of the leading edge

In an aerodynamic tube, an experimental investigation of the development of small natural perturbations in a laminar boundary layer on a plate was made. The measurements were made using a thermoanemometric method with a Mach number M = 2 and a unit Reynolds number Re₁ = 3.1·10⁶ m^–1. An investigation of the effect of blunting of the leading edge of the plate on the development of the perturbations was made. It is shown that blunting decreases the range of unstable frequencies and the region of instability and increases the critical Reynolds number of the loss of stability. In the initial section of the plate there is a rise in the perturbations of all frequencies up to a maximal value, whose coordinate is inversely proportional to the frequency. The development of perturbations in this region is insensitive to the state of the boundary layer. The position of the maximum does not change with blunting of the leading edge.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 4, pp. 65–70, July–August, 1977.