The Role Played by Swift Change of the Stability Characteristic of Mean Flow in Bypass Transition
The scenario of bypass transition is generally described
as follows: the low-frequency disturbances in the free-stream may
generate long stream-wise streaks in the boundary layer, which later
may trigger secondary instability, leading to rapid increase of
high-frequency disturbances. Then possibly turbulent spots emerge,
and through their merging, lead to fully developed turbulence. This
description, however, is insufficient in the sense that it does not
provide the inherent mechanism of transition that during the transition,
a large number of waves with different frequencies and wave numbers
appear almost simultaneously, producing sufficiently large Reynolds
stress, so the mean flow profile can change rapidly from laminar to
turbulent. In this paper, such a mechanism will be figured out from
analyzing DNS data of transition.
[1] Klebanoff P S, Effect of freestream turbulence on the laminar boundary
layer. Bull. Am. Phys. Soc., 1971. Vol. 10, pp. 1323-1327.
[2] Ellingsen T, Palm E, Stability of linear flow. Physics of Fluids, 1975. Vol.
18, pp. 487-488
[3] Hultgren L, Gustavson L, Algebraic growth of disturbances in a laminar
boundary layer. Physics of Fluids, 1981. Vol. 24, no. 6, pp. 1000-1004.
[4] Luchini P, Reynolds number independent instability of the boundary
layer over a flat surface. J. Fluid Mech., 1996. Vol. 327, pp. 101-115.
[5] Andersson P, Berggren M, and Henningson D S, Optimal disturbances
and bypass transition in boundary layers. Physics of Fluids, 1999. Vol. 11,
no. 1, pp. 134-150
[6] Brandt L, Henningson D S, Transition of streamwise streaks in
zero-pressure-gradient boundary layers. J. Fluid Mech., 2002. Vol. 472,
pp. 229-261.
[7] Elofsson P A, Kawakami M, and Alfredsson P H, Experiments on the
stability of streamwise streaks in plane Poiseuille flow. Physics of Fluids,
1999. Vol. 11, pp. 915-930
[8] Andersson P, et al., On the breakdown of boundary layer streaks. Journal
of Fluid Mechanics, 2001. Vol. 428, pp. 29-60
[9] Asai M, Minagawa M, and Nishioka M, The instability and breakdown of
a near-wall low-speed streak. J. Fluid Mech., 2002. Vol. 455, pp. 289-314
[10] Matsubara M, Alfredsson P H, Disturbance growth in boundary layers
subjected to free-stream turbulence. J. Fluid Mech., 2001. Vol. 430, pp.
149-168
[11] Jacobs R G, Durbin P A, Simulations of bypass transition. J. Fluid Mech.,
2001. Vol. 428, pp. 185-212
[12] Luo J, Wang X, and Zhou H, Inherent mechanism of breakdown in
laminar-turbulent transition of plane channel flows. Science in China Ser.
G Physics, Mechanics & Astronomy, 2005. Vol. 48, no. 2, pp. 228-236.
[13] Dong M, Zhang Y M, and Zhou H, A new method for computing
laminar-turbulent transition and turbulence in compressible boundary
layers-PSE plus DNS. Applied Mathematics and Mechanics-English
Edition, 2008. Vol. 29, no. 12, pp. 1527-1534.
[14] Ricco P, Luo J S, and Wu X, Evolution and instability of unsteady
nonlinear streaks generated by free-stream vortical disturbances. J. Fluid
Mech., 2011. Vol. 677, pp. 1-38.
[1] Klebanoff P S, Effect of freestream turbulence on the laminar boundary
layer. Bull. Am. Phys. Soc., 1971. Vol. 10, pp. 1323-1327.
[2] Ellingsen T, Palm E, Stability of linear flow. Physics of Fluids, 1975. Vol.
18, pp. 487-488
[3] Hultgren L, Gustavson L, Algebraic growth of disturbances in a laminar
boundary layer. Physics of Fluids, 1981. Vol. 24, no. 6, pp. 1000-1004.
[4] Luchini P, Reynolds number independent instability of the boundary
layer over a flat surface. J. Fluid Mech., 1996. Vol. 327, pp. 101-115.
[5] Andersson P, Berggren M, and Henningson D S, Optimal disturbances
and bypass transition in boundary layers. Physics of Fluids, 1999. Vol. 11,
no. 1, pp. 134-150
[6] Brandt L, Henningson D S, Transition of streamwise streaks in
zero-pressure-gradient boundary layers. J. Fluid Mech., 2002. Vol. 472,
pp. 229-261.
[7] Elofsson P A, Kawakami M, and Alfredsson P H, Experiments on the
stability of streamwise streaks in plane Poiseuille flow. Physics of Fluids,
1999. Vol. 11, pp. 915-930
[8] Andersson P, et al., On the breakdown of boundary layer streaks. Journal
of Fluid Mechanics, 2001. Vol. 428, pp. 29-60
[9] Asai M, Minagawa M, and Nishioka M, The instability and breakdown of
a near-wall low-speed streak. J. Fluid Mech., 2002. Vol. 455, pp. 289-314
[10] Matsubara M, Alfredsson P H, Disturbance growth in boundary layers
subjected to free-stream turbulence. J. Fluid Mech., 2001. Vol. 430, pp.
149-168
[11] Jacobs R G, Durbin P A, Simulations of bypass transition. J. Fluid Mech.,
2001. Vol. 428, pp. 185-212
[12] Luo J, Wang X, and Zhou H, Inherent mechanism of breakdown in
laminar-turbulent transition of plane channel flows. Science in China Ser.
G Physics, Mechanics & Astronomy, 2005. Vol. 48, no. 2, pp. 228-236.
[13] Dong M, Zhang Y M, and Zhou H, A new method for computing
laminar-turbulent transition and turbulence in compressible boundary
layers-PSE plus DNS. Applied Mathematics and Mechanics-English
Edition, 2008. Vol. 29, no. 12, pp. 1527-1534.
[14] Ricco P, Luo J S, and Wu X, Evolution and instability of unsteady
nonlinear streaks generated by free-stream vortical disturbances. J. Fluid
Mech., 2011. Vol. 677, pp. 1-38.
@article{"International Journal of Medical, Medicine and Health Sciences:49393", author = "Dong Ming and Su Caihong", title = "The Role Played by Swift Change of the Stability Characteristic of Mean Flow in Bypass Transition", abstract = "The scenario of bypass transition is generally described
as follows: the low-frequency disturbances in the free-stream may
generate long stream-wise streaks in the boundary layer, which later
may trigger secondary instability, leading to rapid increase of
high-frequency disturbances. Then possibly turbulent spots emerge,
and through their merging, lead to fully developed turbulence. This
description, however, is insufficient in the sense that it does not
provide the inherent mechanism of transition that during the transition,
a large number of waves with different frequencies and wave numbers
appear almost simultaneously, producing sufficiently large Reynolds
stress, so the mean flow profile can change rapidly from laminar to
turbulent. In this paper, such a mechanism will be figured out from
analyzing DNS data of transition.", keywords = "boundary layer, breakdown, bypass transition,
stability, streak.", volume = "6", number = "3", pages = "34-5", }