The global linear stability properties of the quasi-parallel flow in theneighbourhood of the trailing edge of a thin aerofoil using a WKBH/multiple scales formulation in the limit of large Reynolds nummbers, as originally developed by Monkewitz, Huerre and Chomaz have been investigated. It is shown that the wake is globally unstable to second order in the asymptotic expansion parameter at all Reynolds numbers provides the effective adverse pressure gradient at the trailing edge, which is related to the aeofoil thickness distribution, is sufficient large. For smaller adverse pressure gradients, there exists a critical Reynolds number above which the flow is gobally linearly unstable, but below which it is globally stable. An asymptotic analysis for large wavenumber indicates that the double Blasius profile, corresponding to a zero adverse pressure gradient, may be absolutely unstable
Global linear stability analysis of thin aerofoil wakes
Globale lineare Stabilitaetsanalyse des Nachstroms von duennen Tragfluegeln
Journal of Fluid Mechanics ; 339 ; 239-260
1997
22 Seiten, 17 Bilder, 16 Quellen
Article (Journal)
English