Regeneration and Self-Maintaining of Coherent Structures - Transport and Coherent Structures in Wall Turbulence - page 339

Figure 5.29. Contours of the fluctuations of streamwise velocity at t = 140
resulting from a CRVP disturbance whose parameters are ,

ε = 0.1

p

. The Reynolds number of the basic flow is 3,005.
The levels of fluctuations are

l == l 4

and

pq == 2

x z

. The quantities are rendered
dimensionless in relation to the external scales of the basic flow. For a color
version of this figure, visit www.iste.co.uk/tardu/wallturbulence.zip

± 0.20

The internal structure of the turbulent spot depends little
on the nature of the initial disturbance, if only in qualitative
terms. As an example, Figure 5.30 shows the contours of u
for a WP disturbance. The similarity with Figure 5.29 is
striking. QSVs regenerate at intermediary times in the
spatiotemporal development. We refer the readers to
[HEN 93, [SCH 01] and [NAC 06] for further details about
bypass transition.