Drag Reduction in the Flow of Aqueous Solutions of a Mixture of Cocamidopropyl Betaine and Cocamide DEA

The study presents results of rheological tests and measurements pressure drops occurring during the flow aqueous solutions a mixture drag reducing surfactants: cocamidopropyl betaine (CAPB, zwitterionic surfactant) cocamide DEA (nonionic through straight pipes. Tests were carried out at different CAPB/DEA weight ratios total concentrations surfactants in solution. Rheological demonstrate formation shear-induced structure (SIS) temperature range below 10 °C, which provides evidence for presence wormlike micelles solutions. Drag reduction was observed from 3 to 45 however, above 25 °C degree markedly decreased. lower limit occurs depends on CAPB ratio In higher temperatures, (similarly flexible-chain polymer solutions) onset is noted certain critical value Rec,0 number, whose solution, diameter pipe surfactants. At same time, wall shear stress τw,c0 corresponding approximately independent diameter. number has been linked clouding