Determine whether intra-layer interactions alter near-wall dynamical pathways

Determine whether the observed differences in transition probabilities between the MFU180 and FB180 reflect genuine dynamical differences caused by intra-layer interactions or are partly artifacts of energetic structures drifting across sub-domain boundaries.

Background

The paper compares a minimal flow unit at $Re_\tau\approx180$ (MFU180), which isolates near-wall structures, with a full-scale channel at the same Reynolds number (FB180), where multiple near-wall structures interact. The two cases exhibit differences in transition probabilities, including changes in transitions involving roll, streak, and meander energies.

Because the analysis tracks structures within advecting sub-domains, energetic structures may drift across sub-domain boundaries. The authors state that transition probabilities alone cannot distinguish genuine changes in the underlying dynamics from artifacts associated with this tracking procedure, motivating more detailed motif-based or otherwise diagnostic analysis.