Vortex spots in the boundary layer
Abstract
The evolution of laminar vortex spots in the boundary layer is analyzed by investigating the propagation of twodimensional wave packets in the boundary layer on a flat plate (assuming, for the sake of simplicity, an indefinitely large Reynolds number). Boundarylayer problems modeling the natural origin of wave packets due to the invasion of small vorticity formations into a boundary layer are formulated; a solution of the linearized Prandtl equations with the selfinduced pressure is constructed by using the Laplace transform in time and the Fourier transform in longitudinal coordinate. It is shown that the vortex spot must be a constituent of any transitional process and that the structures of the natural and artificially originating vortex spots, in spite of their difference at the initial stages, become almost identical at some distance from the places of origin.
 Publication:

Fluid Dynamics Transactions
 Pub Date:
 1987
 Bibcode:
 1987FlDyT..13..205R
 Keywords:

 Boundary Layer Flow;
 Flat Plates;
 Two Dimensional Flow;
 Vortices;
 Wave Packets;
 Wave Propagation;
 Cartesian Coordinates;
 Flow Distribution;
 NavierStokes Equation;
 Transformations (Mathematics);
 Turbulent Flow;
 Unsteady Flow;
 Fluid Mechanics and Heat Transfer