Drag reduction effectiveness of macromolecules

Influence of ionic strength on complex formation between poly(ethylene oxide) and cationic surfactant and turbulent wall shear stress in aqueous solution

“…Virk [14] suggested that, at the onset of turbulent drag reduction, the duration of a turbulent burst is of the order of the terminal relaxation time of a macromolecule, and proposed that energy dissipation via macromolecular extension is involved in the mechanism of drag reduction. Hlavacek et al [15] proposed that, in turbulent flow, the solvent contains microdisturbances or turbulence precursors. Macromolecules suppress turbulence by pervading two or more of these microdomains simultaneously and hindering their free movement and growth.…”

Polymer–surfactant complex formation and its effect on turbulent wall shear stress

“…Virk [9] noted that at the onset of turbulent drag reduction the duration of a turbulent burst is of the order of the terminal relaxation time of a macromolecule, and concluded that macromolecular extension is involved in the mechanism of drag reduction. Hlavacek et al [10] proposed that, in turbulent flow, the solvent contains microdisturbances or turbulence precursors. A macromolecule can suppress turbulence by pervading two or more of these microdomains simultaneously and hindering their free movement and growth.…”