Abstract
On the basis of observations with hydrogen bubble photographs the following picture for the origin of the strong instability behind the splitting point of Tollmien waves has been proposed: beyond a certain threshold, characterized by a combination of wave amplitude and Reynolds number and inside the Tollmien wave at a phase position near the center of the cat's-eye there emerges a weak local vorticity peak. This peak does not move relative to the surrounding matter and therefore resembles an ordinary vortex tube. Beyond the threshold it will develop its own warping instability which splits the amplification rate of the Tollmien waves. The three dimensional bending or warping of vortex tubes inside a boundary layer leads to different transport velocities or a convection which stretches the vortex tubes. The stretch in turn produces more convection and so, within the range of one or two wave lengths of the Tollmien waves the vorticity distribution is not only converted into an oblique orientation, but also concentrated into a top- and tail-vortex. The first one will be observed by a hot wire probe as a single spike. It is therefore concluded that the whole development between the splitting point and the appearance of a single spike is a continuous and coherent physical phenomenon.
Preview
Unable to display preview. Download preview PDF.
References
Tollmien, W.: Ober die Entstehung der Turbulenz, 1. Mitt. Nachr. Ges. Wiss. Göttingen, Math. Phys. Klasse 21-44 (1929), NACA TM 609 (1931).
Klebanoff, P.S., Tidstrom, K.O., Sargent, L.M.: The three-dimensional nature of boundary-layer instability. Journ. Fluid Mechanics 12 (1962) pp. 1–34.
Hama, F.R., Williams, D.R., Fasel, H.: Flow field and energy balance according to the spatial linear-stability theory of the Blasius boundary layer. IUTAM Symposium on Laminar Turbulent Transition, Stuttgart, Sept. 16–22, 1979.
Hama, F.R.: Progressive deformation of a perturbated line vortex filament. Physics of Fluids 6 (1963) p. 526.
Hama, F.R.: Streaklines in a perturbated shear flow. Physics of Fluids 5 (1962) p. 644.
Hama, F.R.:, Nutant, J.: Detailed flow field observations in the transition process in a thick boundary layer. Proc. Heat Transfer and Fluid Mach. Inst. (1963) p. 77.
Brown, F.N.M.: See the wind blow. Univ. of Notre Dame (1971) p. 54.
Theodorsen, Th.: The structure of turbulence. Proc. Second Midwestern Conf. Fluid Mechanics 1 (1952). 50 Jahre Grenzschichtforschung. Görtler-Tollmien (1955) Vieweg, Braunschweig.
Author information
Authors and Affiliations
Editor information
Rights and permissions
Copyright information
© 1981 Springer-Verlag
About this paper
Cite this paper
Wortmann, F.X. (1981). Boundary-layer waves and transition. In: Krause, E. (eds) Advances in Fluid Mechanics. Lecture Notes in Physics, vol 148. Springer, Berlin, Heidelberg. https://doi.org/10.1007/BFb0021339
Download citation
DOI: https://doi.org/10.1007/BFb0021339
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-11162-7
Online ISBN: 978-3-540-38635-3
eBook Packages: Springer Book Archive