Connection between classical coherent structures and flow development

Determine the relationship between the classically studied coherent structures in turbulence—intense Reynolds-stress events (Q events), streamwise streaks, and vortices—and the development of turbulent flow fields, specifying how these structures influence the evolution of the flow over time.

Background

The paper examines coherent structures traditionally used to analyze wall-bounded turbulence: Q events associated with momentum transfer and turbulent-kinetic-energy production, streamwise streaks reflecting high/low speed regions, and vortices defined by rotation exceeding shear. The authors introduce a data-driven approach using gradient-SHAP to objectively identify high-importance regions affecting flow prediction and compare these with classical structures. Despite partial correlations, they underscore that the fundamental linkage between these structures and flow development has been uncertain, motivating their analysis.