Three-dimensional distortion of the mean field of a boundary layer by natural oscillations

In boundary layer flows of nonviscous incompressible liquids over a plate, the nonlinear development of perturbations in the laminar-turbulent transition region involves the nucleation and growth of a three-dimensional oscillation field. This leads to the generation of Tollmien-Schlichting waves and to quantitative changes in the structure of the mean flow. The structure of the complex secondary flows in the transition region is analyzed here using a model approach based on the numerical solution of Reynolds equations.