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The turbulence structure of equilibrium boundary layers

Published online by Cambridge University Press:  28 March 2006

P. Bradshaw
Affiliation:
Aerodynamics Division, National Physical Laboratory, Teddington

Abstract

Measurements in three boundary layers, one with constant free-stream velocity and two with power-law variations of free-stream velocity giving ‘moderate’ and ‘strong’ adverse pressure gradients, are presented and discussed. Several unifying features of the turbulent motion, expected to appear in all boundary layers not too far from equilibrium, are identified. The intensity spectra at higher wavenumbers follow the Kolmogorov inertial-subrange law, although the Reynolds number is not particularly high even by laboratory standards: in addition the smaller-scale motion in the outer layer is determined entirely by the local shear stress and the boundary-layer thickness. The large eddy motion increases in strength relative to the general turbulence level as the general turbulence level increases, and the limited evidence available suggests that the large eddies are similar to those in the free mixing layer. In all cases the large eddies contribute a significant proportion of the shear stress in the outer layer.

Type
Research Article
Copyright
© 1967 Cambridge University Press

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References

Batchelor, G. K. 1953 The Theory of Homogeneous Turbulence. Cambridge University Press.
Bkadshaw, P. 1965 Nat. Phys. Lab. Aero Rept. no. 1172 and J. Fluid Mech. (To be published.)
Bradshaw, P. 1966a Nat. Phys. Lab. Aero Rept. no. 1184.
Bradshaw, P. 1966b Nat. Phys. Lab. Aero Rept. no. 1220.
Bradshaw, P. & Ferriss, D. H. 1965a Aero. Res. Counc. Curr. Pap. no. 899.
Bradshaw, P. & Ferriss, D. H. 1965b Nat. Phys. Lab. Aero Rept. no. 1145.
Bradshaw, P., Ferriss, D. H. & Atwell, N. P. 1967 J. Fluid Mech. 28, 593.
Bradshaw, P., Ferriss, D. H. & Johnson, R. F. 1964 J. Fluid Mech. 19, 591.
Bradshaw, P. & Hellens, G. E. 1966 Aero. Res. Counc. R. & M. no. 3437.
Clauser, F. H. 1954 J. Aero. Sci. 21, 91.
Coles, D. 1962 The RAND Corp., Rept. no. R-403-PR.
Fiedler, H. & Head, M. R. 1966 J. Fluid Mech. 25, 719.
Gartshore, I. S. 1966 J. Fluid Mech. 24, 89.
Grant, H. L. 1958 J. Fluid Mech. 4, 149.
Head, M. R. & Rechenberg, I. 1962 J. Fluid Mech. 14, 1.
Klebanoff, P. S. 1955 Nat. Adv. Comm. Aero. Rept. no. 1247.
Lilley, G. M. 1964 Arch. Mech. Stos. 16, 301.
Mellor, G. L. & Gibson, D. M. 1966 J. Fluid Mech. 24, 225.
Rose, W. G. 1966 J. Fluid Mech. 25, 97.
Sandborn, V. A. & Marshall, R. D. 1965 Colorado State Univ. Research Memo, no. 1.
Stratford, B. S. 1959 J. Fluid Mech. 5, 17.
Townsend, A. A. 1956 The Structure of Turbulent Shear Flow. Cambridge University Press.
Townsend, A. A. 1961 J. Fluid Mech. 11, 97.