Excitation of a 3D-wavetrain by a Dirac point source at the wall and its growth in a decelerated laminar boundary layer

In a decelerated laminar boundary layer along a flat plate, a 3D-wavetrain is excited by a time-harmonic Dirac point source at the wall. The evolution of the TS-wavetrain downstream of the source position is calculated by means of the linearized theory with a locally-parallel flow approximation for various frequencies and two different source positions