Hostname: page-component-cd9895bd7-jkksz Total loading time: 0 Render date: 2024-12-26T07:57:00.239Z Has data issue: false hasContentIssue false
  • English
  • Français

A study of turbulent boundary-layer separation and reattachment

Published online by Cambridge University Press:  29 March 2006

A. E. Perry  and
B. D. Fairlie
A. E. Perry
Affiliation:
Department of Mechanical Engineering, University of Melbourne, Parkville, Australia
B. D. Fairlie
Affiliation:
Department of Mechanical Engineering, University of Melbourne, Parkville, Australia Present address: Aeronautical Research Laboratories, Fisherman's Bend, Victoria, Australia.
Get access Rights & Permissions [Opens in a new window]

Abstract

An experimental and theoretical study is made of a suddenly separating and reattaching two-dimensional turbulent boundary layer on a flat surface. A separation bubble is formed on the floor of a wide parallel-sided wind-tunnel duct with the pressure field causing the bubble formation produced by fixing the shape of the flexible roof of the duct. Boundary layers on the roof are controlled and remain attached. It is found that a very satisfactory model for the flow is an inviscid one.

The boundary layer on the floor of the duct is represented by a region of constant vorticity with slip at the boundary, and it is assumed that the separation process is dominated by the interaction between this ‘vortical’ region and the irrotational field between the vortical region and the roof (of prescribed shape). The interface between the rotational and irrotational regions is a free boundary and may be located when all necessary boundary conditions are given. These conditions include two characteristic parameters for the adverse-pressure-gradient turbulent boundary layer which is developing upstream of the region of interest.

The problem is solved by an electrical analog method. The theoretical size and shape of the bubble and positions of separation and reattachment are in agreement with observations. The advantage of the model over most previous attempts to predict separation is that the governing equations are elliptic rather than parabolic or hyperbolic and therefore the interaction between the boundary-layer flow and the irrotational free stream is included in the calculations.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 69 , Issue 4 , 24 June 1975 , pp. 657 - 672
Copyright
© 1975 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

Batchelor, G. K. 1956 J. Fluid Mech. 1, 177.
Clauser, F. H. 1956 Adv. in Appl. Mech. 4, 1.
Coles, D. E. 1956 J. Fluid Mech. 1, 191.
Coles, D. E. & Hirst, E. A. 1968 Proc. AFOSR-IFP-Stanford Conf. on Computation of Turbulent Boundary Layers, vol. 2, p. 55.
Fairlie, B. D. 1973 Ph.D. thesis, University of Melbourne.
Kline, S. J., Morkovin, M. V., Sovran, G. & Cockrell, D. J. 1968 Proc. AFOSR-IFP-Stanford Conf. on Computation of Turbulent Boundary Layers, vol. 1, p. 464.
Kuchemann, D. 1967 Z. Flugwiss. 15, 292.
Lighthill, M. J. 1963 Laminar Boundary Layers (ed. L. Rosenhead), p. 46. Oxford University Press.
Oswatitsch, K. 1958 In Grenzschichtforshung (ed. H. Goertler), p. 299. Springer.
Perry, A. E. & Fairlie, B. D. 1974 Adv. in Geophys. B, 18, 299.
Perry, A. E. & Schofield, W. H. 1973 Phys. Fluids, 16, 2068.
Sandborn, V. A. 1959 N.A.S.A. Memo. no. 2–5-59E.
Smith, P. D. 1970 R.A.E. Tech. Memo. Aero 1217.
Stratford, B. S. 1959 J. Fluid Mech. 5, 1.
Swannell, J. H. 1963 Exp. Mech. 3, 279.
Taulbee, D. B. & Robertson, J. M. 1972 J. Basic Engng, Trans. A.S.M.E. D, 94, 544.
Townsend, A. A. 1960 J. Fluid Mech. 8, 143.