Nonlinear wavepackets in boundary layers

Abstract

The nonlinear evolution of streamwise modulated three-dimensional waves in boundary layers was investigated. Three nonlinear stages were identified. The first was related to oblique transition and transient growth. The second involved Klebanoff instability. The third was a subharmonic instability. Associated with the modulation, a mechanism of production of subharmonic waves was also identified. This provided the deterministic seeds for the subharmonic instability. © 2006 Springer.