Structured input–output analysis of transitional wall-bounded flows

Input-output analysis of transitional channel flows has proven to be a valuable analytical tool for identifying important flow structures and energetic motions. The traditional approach abstracts the nonlinear terms as forcing that is unstructured, in sense this not directly tied underlying nonlinearity dynamics. This paper instead employs structured singular value-based preserves certain input-output properties function an effort recover larger range key features identified through analysis, experiments, direct numerical simulation (DNS) flows. Application method plane Couette Poiseuille leads only identification streamwise coherent predicted approaches, but also characterization oblique those requiring least energy induce transition agreement with DNS studies, optimal perturbation analysis. proposed captures recently observed turbulent bands have been linked experiments very large size. ability identify amplification varying from both regimes suggests allows one maintain effects associated weakening lift-up mechanism, which known dominate linear operator. Capturing effect enables prediction wider within modeling paradigm.