Hostname: page-component-77c89778f8-cnmwb Total loading time: 0 Render date: 2024-07-16T22:41:36.887Z Has data issue: false hasContentIssue false

Boundary-layer transition triggered by hairpin eddies at subcritical Reynolds numbers

Published online by Cambridge University Press:  26 April 2006

Masahito Asai
Affiliation:
Department of Aerospace Engineering, Tokyo Metropolitan Institute of Technology, Asahigaoka 6-6, Hino, Tokyo 191, Japan
Michio Nishioka
Affiliation:
Department of Aerospace Engineering, University of Osaka Prefecture, Gakuencho 1-1, Sakai, Osaka 593, Japan

Abstract

Subcritical transition in a flat-plate boundary layer is examined experimentally through observing its nonlinear response to energetic hairpin eddies acoustically excited at the leading edge of the boundary-layer plate. When disturbed by the hairpin eddies convecting from the leading edge, the near-wall flow develops local three-dimensional wall shear layers with streamwise vortices. Such local wall shear layers also evolve into hairpin eddies in succession to lead to the subcritical transition beyond the x-Reynolds number Rx = 3.9 × 104, where the momentum thickness Reynolds number Rθ is 127 for laminar Blasius flow without excitation, and is about 150 under the excitation of energetic hairpin eddies. It is found that in terms of u- and v-fluctuations, the intensity of the near-wall activity at this critical station is of almost the same order as or slightly less than that of the developed wall turbulence. The development of wall turbulence structure in this transition is also examined.

Type
Research Article
Copyright
© 1995 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

Acarlar, M. S. & Smith, C. R. 1987a A study of hairpin vortices in a laminar boundary layer. Part 1. Hairpin vortices generated by a hemisphere protuberance. J. Fluid Mech. 175, 141.Google Scholar
Acarlar, M. S. & Smith, C. R. 1987b A study of hairpin vortices in a laminar boundary layer. Part 2. Hairpin vortices generated by fluid injection. J. Fluid Mech. 175, 4383.Google Scholar
Asai, M. & Nishioka, M. 1989 Origin of the peak-valley wave structure leading to wall turbulence. J. Fluid Mech. 208, 123.Google Scholar
Asai, M. & Nishioka, M. 1990 Development of wall turbulence in Blasius flow. In Laminar-Turbulent Transition (ed. D. Arnal & R. Michel), pp. 215224. Springer.
Bayly, B. J., Orszag, S. A. & Herbert, Th. 1988 Instability mechanisms of boundary layer transition. Ann. Rev. Fluid Mech. 20, 359391.Google Scholar
Bertolotti, F. P., Herbert, Th. & Spalart, P. R. 1992 Linear and nonlinear stability of the Blasius boundary layer. J. Fluid Mech. 242, 441474.Google Scholar
Carlson, D. R., Widnall, S. E. & Peeters, M. E. 1982 A flow visualization of transition in plane Poiseuille flow. J. Fluid Mech. 121, 487505.Google Scholar
Coles, D. D. & Hirst, E. A. (Eds.) 1968 Proc. AFOSR-IFP-Stanford Conf. on Computation of Turbulent Boundary Layers, Stanford University.
Drazin, P. G. & Reid, W. H. 1981 Hydrodynamic Stability, pp. 211239. Cambridge University Press.
Fasel, H. 1990 Numerical simulation of instability and transition in boundary layer flows. In Laminar-Turbulent Transition (ed. D. Arnal & R. Michel), pp. 587598. Springer.
Fasel, H. & Konzelman, U. 1990 Non-parallel stability of a flat-plate boundary layer using the complete Navier-Stokes equations. J. Fluid Mech. 221, 311347.Google Scholar
Gaster, M. 1969 On the flow along swept leading edge. Aero. Q. 18, 165184.Google Scholar
Haidari, A. H. & Smith, C. R. 1994 The generation and regeneration of single hairpin vortices. J. Fluid Mech. 277, 135162.Google Scholar
Hama, F. R. & Nutant, J. 1963 Detailed flow-field of transition process in a thick boundary layer. In Proc. 1963 Heat Transfer and Fluid Mech. Inst., Stanford University, pp. 7793.
Henningson, D. S. & Alfredsson, P. H. 1987 The wave structure of turbulent spots in plane Poiseuille flow. J. Fluid Mech. 178, 405421.Google Scholar
Henningson, D. S. & Kim, J. 1991 On turbulent spots in plane Poiseuille flow. J. Fluid Mech. 228, 183205.Google Scholar
Herbert, Th. 1988 Secondary instability of boundary layers. Ann. Rev. Fluid Mech. 20, 487526.Google Scholar
Kachanov, Yu. S. 1994 Physical mechanisms of laminar-boundary-layer transition. Ann. Rev. Fluid Mech. 26, 411482.Google Scholar
Klebanoff, P. S., Tidstrom, K. D. & Sargent, L. M. 1962 The three-dimensional nature of boundary layer instability. J. Fluid Mech. 12, 134.Google Scholar
Klingmann, B. G. B. 1992 On transition due to three-dimensional disturbances in plane Poiseuille flow. J. Fluid Mech. 240, 167195.Google Scholar
Kovasznay, L. S. G., Komoda, H. & Vasudeva, B. R. 1962 Detailed flow field in transition. In Proc. 1962 Heat Transfer and Fluid Mech. Inst., Stanford University, pp. 126.
Matsui, T. 1980 Visualization of turbulent spots in the boundary layer along a flat plate in a water flow. In Laminar-Turbulent Transition (ed. R. Eppler & H. Fasel), pp. 288296. Springer.
Morkovin, M. V. 1988 Recent insights into instability and transition. AIAA-88-3675.Google Scholar
Nishioka, M. & Asai, M. 1984 Evolution of Tollmien-Schlichting waves into wall turbulence. In Turbulence and Chaotic Phenomena in Fluids (ed. T. Tatsumi), pp. 8792. North-Holland.
Nishioka, M. & Asai, M. 1985 Some observations of the subcritical transition in plane Poiseuille flow. J. Fluid Mech. 150, 441450.Google Scholar
Nishioka, M., Asai, M. & Iida, S. 1980 An experimental investigation of the secondary instability. In Laminar-Turbulent Transition (ed. R. Eppler & H. Fasel), pp. 3746. Springer.
Nishioka, M., Asai, M. & Iida, S. 1981 Wall phenomena in the final stage of transition to turbulence. In Transition and Turbulence (ed. R. E. Meyer), pp. 113126. Academic.
Nishioka, M., Iida, S. & Ichikawa, Y. 1975 An experimental investigation of the stability of plane Poiseuille flow. J. Fluid Mech. 72, 731751.Google Scholar
Nishioka, M. & Morkovin, M. V. 1986 Boundary-layer receptivity to unsteady pressure gradients: experiments and overview. J. Fluid Mech. 171, 219261.Google Scholar
Orszag, S. A. 1971 Accurate solution of the Orr-Sommerfeld stability equation. J. Fluid Mech. 50, 689703.Google Scholar
Poll, D. I. A. 1979 Transition in the infinite swept attachment line boundary layer. Aero. Q. 30, 607629.Google Scholar
Sandham, N. D. & Kleiser, L. 1992 The late stages of transition to turbulence in channel flow. J. Fluid Mech. 245, 319348.Google Scholar
Smith, C. R., Walker, J. D. A., Haidari, A. H. & Sobrun, U. 1991 On the dynamics of near-wall turbulence. Phil. Trans. R. Soc. Lond. A 336, 131175.Google Scholar