J. Myska et Jl. Zakin, DIFFERENCES IN THE FLOW BEHAVIORS OF POLYMERIC AND CATIONIC SURFACTANT DRAG-REDUCING ADDITIVES, Industrial & engineering chemistry research, 36(12), 1997, pp. 5483-5487
Research on cationic surfactant drag-reducing additives has grown in r
ecent years because of their repairability after shear degradation, ma
king them suitable for potential applications in recirculation flows s
uch as district heating and district cooling systems. Substantial diff
erences between their flow behaviors and those of high-polymer, drag-r
educing additives have been found. These include the influence of pres
hearing, the effect of mechanical shear on degradation, the influence
of tube diameter, maximum drag-reduction effectiveness, and the shape
of their mean velocity profiles. Examples of these different flow beha
viors are described. The differences suggest that the mechanisms for c
ausing drag reduction may be different for the two types of additives.