To nonlinear disturbance interactions in 3D supersonic boundary-layer

Experimental data on the nonlinear wave train development in 3D supersonic boundary layer over a 45° swept-wing at Mach number 2 are presented. Travelling artificial disturbances were introduced in the boundary layer by periodical glow discharge at frequencies 10 and 20 kHz. It is shown that the additional peaks in β′-spectra arise for both subharmonic and fundamental frequencies. The experiments indicate the presence of oblique breakdown mechanism in 3D supersonic boundary layer. The three-wave triad consisting of two primary travelling waves and one steady wave is discussed. The linear stability theory results demonstrate the possibility of the existence for such triads.Experimental data on the nonlinear wave train development in 3D supersonic boundary layer over a 45° swept-wing at Mach number 2 are presented. Travelling artificial disturbances were introduced in the boundary layer by periodical glow discharge at frequencies 10 and 20 kHz. It is shown that the additional peaks in β′-spectra arise for both subharmonic and fundamental frequencies. The experiments indicate the presence of oblique breakdown mechanism in 3D supersonic boundary layer. The three-wave triad consisting of two primary travelling waves and one steady wave is discussed. The linear stability theory results demonstrate the possibility of the existence for such triads.