Mechanism of instability of Falkner-Skan flows

Malik, M and Mathew, J and Dey, J (2003) Mechanism of instability of Falkner-Skan flows. In: Acta Mechanica, 164 (1-2). pp. 75-89.

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Abstract

It is shown that the mechanism of linear instability of boundary-layer flows driven by favorable and adverse pressure gradients can be understood as a kinematic resonant interaction between inviscid and viscous partial modes. This kind of interaction has been proposed by Baines, Majumdar and Mitsudera [4] for the Blasius boundary layer. Here, this proposal has been examined for more general flows and quantitative confirmation has been obtained. Piecewise linear approximations of Falkner-Skan velocity profiles are taken as the mean flows. To understand the mechanism, it proves sufficient to examine eigensolutions of the viscous part obtained by enforcing no slip. This leads to the prediction of the parameters for maximum growth in the space of Reynolds number and wave number. In the case of adverse pressure gradient the inviscid flow itself is unstable due to the presence of an inflexion point. We show that the instability mechanism stated above has a role in the flows of this kind, too.

Item Type:	Journal Article
Publication:	Acta Mechanica
Publisher:	Springer-Verlag
Additional Information:	Copyright of this article belongs to Springer-Verlag.
Department/Centre:	Division of Mechanical Sciences > Aerospace Engineering(Formerly Aeronautical Engineering)
Date Deposited:	25 Apr 2007
Last Modified:	19 Sep 2010 04:37
URI:	http://eprints.iisc.ac.in/id/eprint/10659

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