Three-dimensional wave perturbations in the laminar boundary layer, where the stream profile has a point of deflection, are considered. The dispersion relation for frequency as a function of wave number is shown to have typically two branches (corresponding to positive and negative energies), which merge at a point where the group velocity of wave perturbation becomes infinite. The dissipative property of the medium is taken into account. It is shown that the region of wave instability constitutes only a portion of the region where negative-energy waves exist.
|Number of pages||4|
|Publication status||Published - Sep 1997|