Polymer degradation of dilute solutions in turbulent drag reducing flows in a cylindrical double gap rheometer device

Pereira, Anselmo Soeiro; Soares, Edson J.

doi:10.1016/j.jnnfm.2012.05.001

Cited by 87 publications

(56 citation statements)

References 44 publications

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“…They proposed a model of the polymeric chain conformations based on statistical mechanics, and the effects on the DR efficiency and mechanical degradation of the polymer chains in a turbulent flow were established by considering the relationship between the extent of mechanical degradation of the polymer chains and the flow time. Recently, Pereira and Soares [35] further showed that the DR increased with time to reach a maximum, before decreasing due to chain degradation. They also presented the relative DR quantity, defined as the ratio of the current DR to the maximum DR obtained before degradation.…”

Section: Mechanism Of Turbulent Drag Reduction With Polymersmentioning

confidence: 94%

Applications of Water-Soluble Polymers in Turbulent Drag Reduction

2017

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Water-soluble polymers with high molecular weights are known to decrease the frictional drag in turbulent flow very effectively at concentrations of tens or hundreds of ppm. This drag reduction efficiency of water-soluble polymers is well known to be closely associated with the flow conditions and rheological, physical, and/or chemical characteristics of the polymers added. Among the many promising polymers introduced in the past several decades, this review focuses on recent progress in the drag reduction capability of various water-soluble macromolecules in turbulent flow including both synthetic and natural polymers such as poly(ethylene oxide), poly(acrylic acid), polyacrylamide, poly(N-vinyl formamide), gums, and DNA. The polymeric species, experimental parameters, and numerical analysis of these water-soluble polymers in turbulent drag reduction are highlighted, along with several existing and potential applications. The proposed drag reduction mechanisms are also discussed based on recent experimental and numerical researches. This article will be helpful to the readers to understand better the complex behaviors of a turbulent flow with various water-soluble polymeric additives regarding experimental conditions, drag reduction mechanisms, and related applications.

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Section: Mechanism Of Turbulent Drag Reduction With Polymersmentioning

confidence: 94%

Applications of Water-Soluble Polymers in Turbulent Drag Reduction

2017

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“…Analyzing the concept of drag reduction with a universally acceptable theory on molecular degradation of DRAs would be a difficult one, many interdisciplinary relationships between chemistry and fluid mechanics are parts of the major factor contributing to such, different works have been reported in this respect with respect to molecular weight, concentration, temperature and Reynolds number on drag reduction effectiveness, some of these are (Nakano and Minoura, 1975;Rho et al 1996;Pereira and Soares, 2012).…”

Section: Molecular Degradationmentioning

confidence: 99%

Investigating the Drag Reduction Performance of Rigid Polymer–Carbon Nanotubes Complexes

Oluwasoga¹,

Abdulbari²

2016

JAFM

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Transporting liquids in commercial Pipeline is very expensive due to cost incurred in the installation of pumping stations. This cost can be reduced by polymeric additives. However, these polymeric additives degrade over time as a result of mechanical stress the fluids are subjected to. Previous efforts to address these problems have not been successful. It is thus inevitable to find alternative means of reducing the frictional drag in fluid flow. In this present work, the experimental study of rigid polymer, Carbon Nanotubes (CNT) Nanofluids and the complex mixtures for drag reduction in a rotating disk apparatus. The finding shows that, about 50% drag reduction was achieved; a comparative study was made on the drag reduction of both complex and nanofluids, where both were able to reduce drag, however at different concentrations. It could thus be concluded that combination of xanthan gum and Carbon nanotubes could reduce drag at a particular concentration

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“…The investigation of the degradation of the nonionic surfactant solution is quite important for the application for the circulating system. Up to the present time, the polymer degradation has been comprehensively investigated for the pipe flow [26,30,42,10], boundary layer flow [9], and flow in a cylindrical double gap rheometer [27]. For the nonionic surfactant solutions, on the other hand, extensive studies on degradation are few [12].…”

Section: Introductionmentioning

confidence: 99%