| Abstract: | The flow stability in a boundary layer with an inhomogeneous spanwise-periodic velocity profile modeling the streaky structure that develops at a high level of turbulence of the incident flow is analyzed in the three-dimensional formulation for perturbations with an arbitrary transverse period. It is shown that in the presence of inhomogeneity the dispersion relation for the Tollmien-Schlichting waves is split into two branches periodic in the transverse wave number, which correspond to symmetric and antisymmetric modes. The solution for the packet of inhomogeneous-flow modes generated by localized time-periodic fluid injection/ejection is found. The shape of this packet corresponds qualitatively to the shape of the Tollmien-Schlichting wave packet, but the fine perturbation structure inside it is sharply different. |
