ON THE THREE DIMENSIONAL INSTABILITY MODES IN BOUNDARY LAYERS.

The purpose of this paper is to substantiate our guess that between linear and nonlinear stages in a transition process there is a weak nonlinear stage for which some important flow phenomena can be described by linear theory. To substantiate this observation we carried out extensive calculations and compared the results with the available experimental data involving three dimensional instability modes. The comparison is encouraging. The influences of adverse pressure gradient on the three dimensional wave structure and its consequences have been studied. (Author abstract. )