Near-Wall Coherent Structures: History, Identification and Detection - Transport and Coherent Structures in Wall Turbulence - page 134

non-exhaustive publications representative of this period are
[WIL 72], [WAL 72], [LU 73], [ECK 74], [BLA 76], [WAL 77],
[CHE 78] and [HEA 81]. The concept of attached structures
proposed by Townsend [TOW 76] was also reviewed during
this period by Perry and Chong [PER 82], as discussed in
detail in [TAR 11a] and [TAR 11b].
Figure 3.4. Flow visualizations by particle tracking in a channel flow
determined by Kim et al. [KIM 87] using DNS. The streaklines are obtained
by emission across a spanwise line to settle in the visualizations by
hydrogen bubbles shown in Figure 3.2. a) Top view of the channel and
b) side view