Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-18T21:26:38.001Z Has data issue: false hasContentIssue false

The dynamics of turbulence near a wall according to a linear model

Published online by Cambridge University Press:  28 March 2006

Gerald Schubert
Affiliation:
College of Engineering, University of California, Berkeley
G. M. Corcos
Affiliation:
College of Engineering, University of California, Berkeley

Abstract

The dynamics of turbulent velocity fluctuations in and somewhat outside the viscous sublayer are examined by linearizing the equations of motion around the known mean velocity profile. The rest of the boundary layer is assumed to drive the motion in the layer by means of a fluctuating pressure which is independent of distance from the wall. The equations, which are boundary-layer approximations to the Orr-Sommerfeld equations, are thus treated as a non-homogeneous system and solved by convergent power series. The solutions which exhibit the strong role of viscosity throughout the layer considered provide a model endowed with many of the known features of turbulence near a wall. In particular, the phase angle between streamwise and normal fluctuations is found to be in plausible agreement with experiments. An important role is ascribed by the solutions to the displacement of the mean velocity by the normal fluctuations. The impedance of the layer is found to be anisotropic in that it favours fluctuations with a much larger scale in the streamwise than in the spanwise direction. For such disturbances, the ratio of turbulent intensity to the intensity of the pressure fluctuations approximates the experimental ratio. According to the solutions it is primarily the spanwise component of the pressure gradient which is responsible for the intense level of turbulence very near the wall. The model apparently underestimates the amplitude ratio of normal to streamwise components of the velocity.

Type
Research Article
Copyright
© 1967 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

Bull, M. K., Wilby, J. F. Blackman, D. R. 1963 Univ. of Southampton AASU Rept. no. 243, part 1
Coles, D. 1953 Jet Propulsion Laboratory Rept. no. 20–69.
Corcos, G. M. 1964 J. Fluid Mech. 18, 353.
Einstein, H. A. & Li, H. 1956 ASCE Proc. 82, no. EM 2.
Grant, H. L. 1958 J. Fluid Mech. 4, 149.
Hanratty, T. J. 1956 AICHE J. 2, no. 3, 359–362.
Kawamura, M. 1960 J. Science, Hiroshima Univ. (Series A), 241, 403.
Kistler, A. 1962 Mecanique de la Turbulence, Centre National de la Recherche Scientifique, Publication no. 108, 287.
Klebanoff, P. W. 1954 NACA Technical note no. 3178.
Landahl, M. 1965 A wave-guide model for turbulent shear flow. NASA CR 317.
Lighthill, M. J. 1963 Laminar Boundary Layers (L. Rosenhead, editor). Oxford: Clarendon Press.
Lilley, G. M. 1963 AGARD Rept. no. 454.
Prandtl, L. 1925 ZAMM, 5, 136.
Priestley, J. T. 1965 National Bureau of Standards, Rept. no. 8942.
Schlichting, H. 1960 Boundary Layer Theory. London: Pergamon Press.
Sternberg, J. 1962 J. Fluid Mech. 13, 241.
Sternberg, J. 1965 AGARDOGRAPH 97.
Willmarth, W. W. & Wooldridge, C. F. 1962 J. Fluid Mech. 14, 187.
Willmarth, W. W. & Wooldridge, C. F. 1963 AGARD Rept. no. 456.