Receptivity to Roughness and Vortical Free-Stream Modes

Authors: Schrader, L.-U., Brandt, L.B., Henningson, D.S.H.
Document Type: Article
Pubstate: Published
Journal: Advances in Turbulence XI, Proceedings of the eleventh European Turbulence Conference
Volume: 117   29-31
Year: 2007


Transition in boundary layers is due to the growth of unstable disturbances finally breaking down to turbulence. Numerous experimental investigations have shown that the initial conditions of these unstable waves strongly depend on the external perturbation environment. Therefore, this study is devoted to the initial receptivity phase.

In particular, the Falkner-Skan-Cooke boundary layer is considered here. The misalignment between pressure gradient and free-stream velocity induces an inflectional wall-normal profile supporting inviscid instability. A number of papers in literature deal with the receptivity to surface roughness. This study also includes the receptivity to vortical free-stream perturbations.