Supplementary Material for “Structural organization of large and very-large scales in turbulent pipe flow simulation” J. R. Baltzer, R. J. Adrian, and X. Wu 1 Structure Lengths at y + = 30 While the main text focused on structure lengths at y/R =0.15, the structure lengths are also similarly calculated nearer the wall at y + = 30 in figure I. While this position is where the buffer and logarithmic layers meet with relatively strong influence of the near-wall motions, which are not the emphasis of this study, the length distribution is instructive. The histogram uses the same threshold value of u ′ = −0.1U bulk that was used in the main text for y/R =0.15, where the this value was approximately the magnitude of the local u ′ rms value of 0.0995U bulk . At y + = 30, the local u rms value is 0.133U bulk , so the threshold corresponds to a relatively weaker fluctuation when scaled by rms u ′ fluctuation, thereby promoting the extraction of longer structures. The results indicate that long motions also exist in this region, consistent with footprints of taller VLSMs extending downward near the wall (Hutchins & Marusic, 2007), which will be further discussed. 10 -3 10 -2 10 -1 10 0 10 1 10 2 10 3 (a) 0 0.05 0.1 (c) -1 0 1 2 0 5 10 15 20 25 30 -0.2 -0.15 -0.1 -0.05 0 (b) 0.01 0.02 0.03 0 5 10 15 20 25 30 -0.2 -0.15 -0.1 -0.05 0 (d) l x /R u thr /U bulk 〈n str 〉 l x /R u thr /U bulk 〈A clust 〉 /A Figure I: Histograms of streamwise length of contiguous regions of negative u ′ fluctuation as in figure 3, except y + = 30 (a) and (c) correspond to a threshold value of u ′ thr /U bulk = −0.10. 1