Characteristics of Weakly Nonlinear Interaction of the Instability Waves in a Supersonic Boundary Layer

The results of an experimental study of weakly nonlinear interaction mechanisms of the instability waves in a supersonic boundary layer on flat plate at Mach number М = 2 are presented in the paper. The downstream evolution of artificial disturbances of small amplitude was studied experimentally. The wave characteristics of traveling disturbances were determined. Obtained, that disturbances evolution at basic frequency was happen in according to the linear theory of hydrodynamical stability. Confirmed, that subharmonical resonance on asymmetrical wave triplet was the reason of amplification of the high inclined subharmonic pulsations. The role of high-frequency disturbances was not significant in the region of weakly nonlinear interactions. The initial stage of a parametrical resonance was characterized by appearance of a stationary wave, jumps of a phase on 180° on frequency of a subharmonic in a cross-section direction, and also not symmetry in amplitude β-spectra.

Keywords:
supersonic boundary layer, instability, wave train, nonlinear, laminar-turbulent transition.
УДК 532.526

Characteristics of Weakly Nonlinear Interaction of the Instability Waves in a Supersonic Boundary Layer