Hostname: page-component-77c89778f8-m8s7h Total loading time: 0 Render date: 2024-07-18T19:32:55.670Z Has data issue: false hasContentIssue false

A dynamical systems approach to the early stages of boundary-layer transition

Published online by Cambridge University Press:  26 April 2006

Abstract

A series of experiments has been performed on a laminar flat-plate boundary layer undergoing transition to turbulence. Reproducible disturbances were introduced via a loudspeaker embedded at some upstream location. Time series of the velocity fluctuations were obtained at a sequence of downstream locations using hot-wire anemometry and the phase portraits were reconstructed at each position. A new technique has been used to estimate the number of independent modes. Nonlinear maps were then fitted that transform the portrait at one streamwise location onto the portrait at the neighbouring downstream position. In this way the spatial evolution of disturbances is modelled explicitly. These maps agree with classical linear stability theory for small disturbances, and appear to give rise to ‘Smale horse-shoe’-like behaviour for larger amplitude disturbances. This may provide a mechanism for generating sensitive dependence on initial conditions, and illustrates a possible role for low-dimensional chaos in boundary-layer transition.

Type
Research Article
Copyright
© 1993 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Broomhead, D. S. & King, G. P. 1986 Extracting qualitative dynamics from experimental data. Physica D. 20, 217236.Google Scholar
Casdagli, M. 1989 Nonlinear prediction of chaotic time series. Physica D. 35, 335356.Google Scholar
Gaster, M. 1962 A note on the relation between temporally-increasing and spatially-increasing disturbances in hydrodynamic stability. Phys. Rev. Lett.. 59, 845848.Google Scholar
Gaster, M. 1990 The nonlinear phase of wave growth leading to chaos and breakdown to turbulence in a boundary layer as an example of an open system. Proc. R. Soc. Lond.. A 430, 324.Google Scholar
Guckenheimer, J. & Holmes, P. 1986 Nonlinear Oscillators, Dynamical Systems and Bifurcations of Vector Fields, 2nd edn. Springer.
Healey, J. J. 1993 Identifying finite dimensional behaviour from broadband spectra. Phys. Lett. A (submitted.)Google Scholar
Hussain, A. K. M. F. 1986 Coherent structures and turbulence. J. Fluid Mech.. 173, 303356.Google Scholar
Jordinson, R. 1970 The flat plate boundary layer. Part 1. Numerical integration of the Orr–Sommerfeld equation. J. Fluid Mech.. 43, 801811.Google Scholar
Lumley, J. L. 1981 Coherent structures in turbulence. In Transition and Turbulence (ed. R. E. Meyer), pp. 215242. Academic.
Powell, M. J. D. 1985 Radial basis functions for multivariable interpolation: A review. Proc. IMA Conf. on Algorithms for the Approximation of Functions and Data. RMCS Shrivenham, UK.
Press, W. H., Flannery, B. P., Teukolsky, S. A. & Vetterling, W. T. 1986 Numerical Recipes. Cambridge University Press.
Takens, F. 1981 Detecting strange attractors in turbulence. In Dynamical Systems and Turbulence, Lecture Notes in Mathematics, vol. 898 (ed. D. A. Rand & L.-S. Young), p. 366. Springer.
White, F. M. 1974 Viscous Fluid Flow. McGraw-Hill.
Wiggins, S. 1988 Global Bifurcations and Chaos. Springer.