
Sublayer of a turbulent boundary layer. A suspension of aluminum particles in a stream of water shows the streaks in the sublayer of a turbulent boundary layer on a flat wall. A mirror is used to show a simultaneous side view.
Reprinted from Figure 7/Plate 4, Cantwell, B.J., Coles, D. and Dimotakis, P. "Structure and entrainment in the plane of symmetry", Journal of Flluid Mechanics, Vol. 87, 1978; pp. 641-672. © Cambridge University Press 1977. Reprinted with permission of Cambridge University Press.