Prediction of polymer extension, drag reduction, and vortex interaction in direct numerical simulation of turbulent channel flows

Hydrodynamic and viscoelastic interactions between the turbulent fluid within a channel at [Formula: see text] polymeric phase are investigated numerically using multiscale hybrid approach. Direct numerical simulations performed to predict continuous Brownian dynamics finitely extensible nonlinear elastic dumbbell approach carried out model trajectories of polymer extension vectors flow, parallel computations achieve reasonable computation timeframes on large-scale flows. Upon validating configuration solver against theoretical predictions in equilibrium conditions, with excellent agreement observed, distributions velocity gradient tensor components analyzed throughout flow wall-normal regions. Impact stretching is discussed, streamwise dominant close wall, driven by high gradients velocity. In this case, it shown that chains already possessing extensions may attempt orientate more direction, causing curling effect. These effects observed instantaneous snapshots extension, bulk Weissenberg number show increased leads stretched configurations orientated conformities whereas, log-law regions, polymers tend trace turbulence structures. Chain orientation angles also considered, demonstrating little influence isotropic Polymer–fluid coupling implemented through contribution stress tensor. The effect relaxation time drag reduction greater numbers leading impactful reduction. Finally, invariants calculated for drag-reduced flows, having significant impact Q–R diagrams, presence narrowing range values wall regions structures become two-dimensional.