Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-21T04:37:55.086Z Has data issue: false hasContentIssue false
  • English
  • Français

Influence of the amplitude of a solid wavy wall on a turbulent flow. Part 2. Separated flows

Published online by Cambridge University Press:  19 April 2006

Daniel P. Zilker  and
Thomas J. Hanratty
Daniel P. Zilker
Affiliation:
Department of Chemical Engineering, University of Illinois, Urbana
Thomas J. Hanratty
Affiliation:
Department of Chemical Engineering, University of Illinois, Urbana
Get access Rights & Permissions [Opens in a new window]

Abstract

A study has been carried out of turbulent flow over a sinusoidally shaped solid boundary of large enough amplitude that the flow separates from the downstream side of the wave. Measurements are presented of the conditions under which separated flows exist, the extent of the separated region and the variation of the pressure and shear stress along and the velocity profile above the wavy surface. The results are consistent with the model D turbulent solution of the linear momentum equations discussed in Zilker, Cook & Hanratty (1977, hereafter referred to as I) in that reversed flows are possible for wave height to wavelength ratios 2a/λ > 0·033 and in that the range of flow rates for which reversed flows exist increases with increasing 2a/λ. For non-separated flows and for flows with thin separated regions the amplitude of the pressure variation changes linearly with wave height; however, for very large amplitude waves with thick separated regions it is much less sensitive to variations in wave height since the external flow that controls the pressure variation sees a wave profile consisting of a composite of the solid wave and the separated region. The variation of the velocity field along the wave surface in the non-separated region is similar to that predicted by linear theory for small amplitude waves. The flow separates in a region of increasing pressure and reattaches in the region where the pressure on the wave surface is a maximum. A large increase in the wall shear stress is noted immediately downstream of reattachment.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 90 , Issue 2 , 29 January 1979 , pp. 257 - 271
Copyright
© 1979 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

Beebe, P. 1972 Turbulent flow over a wavy boundary. Ph.D. thesis, Colorado State University, Fort Collins.
Cook, G. W. 1970 Turbulent flow over solid wavy surfaces. Ph.D. thesis, University of Illinois, Urbana.
Hsu, S. T. & Kennedy, J. F. 1971 J. Fluid Mech. 47, 481.
Kendall, J. M. 1970 J. Fluid Mech. 41, 259.
Motzfield, H. 1937 Z. angew. Math. Mech. 17, 193.
Sigal, A. 1971 An experimental investigation of the turbulent boundary layer over a wavy wall. Ph.D. thesis, California Inst. Tech., Pasadena.
Son, J. S. & Hanratty, T. J. 1969 J. Fluid Mech. 35, 353.
Stanton, T., Marshall, D. & Houghton, R. 1932 Proc. Roy. Soc. A 137, 283.
Taylor, P. A., Gent, P. R. & Keen, J. M. 1976 J. Roy. Astr. Soc. 44, 177.
Thorsness, C. B. 1975 Transport phenomena associated with flows over a solid wavy surface. Ph.D. thesis, Department of Chemical Engineering, University of Illinois, Urbana.
Thorsness, C. B. & Hanratty, T. J. 1977 Turbulent flows over wavy surfaces. Proc. Symp. Turbulent Shear Flows, Penn. State Univ.
Thorsness, C. B., Morrisroe, P. E. & Hanratty, T. J. 1978 Chem. Engng Sci. 30, 579.
Zagustin, K., Hsu, E. Y., Street, R. L. & Perry, B. 1966 Flow over a moving boundary in relation to wind-generated waves. Dept. Civil Engng, Stanford Univ. Tech. Rep. no. 60.Google Scholar
Zilker, D. P. 1976 Flow over wave surfaces. Ph.D. thesis, University of Illinois, Urbana.
Zilker, D. P., Cook, G. W. & Hanratty, T. J. 1977 J. Fluid Mech. 82, 29.