Excitation of Tollmien-Schlichting waves in a boundary layer on a vibrating surface

Results of an experimental study of the generation of Tollmien-Schlichting waves in a boundary layer on a vibrating surface are reported. It is shown that small localized vibrations of the surface are transformed to a boundary-layer instability wave; the transformation coefficient is estimated experimentally. For a constant vibration amplitude, the transformation to an equivalent Tollmien-Schlichting wave is shown to occur in the same way for different excitation frequencies.