A review on drag reduction with special reference to micellar systems

Shenoy, Aroon

doi:10.1007/bf01410471

Cited by 103 publications

(72 citation statements)

References 208 publications

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“…As a result of the non-uniform stress distribution during experiments, these micelles are oriented such that their long axis is parallel to the flow direction in shear. Although, the mechanical stability of the anionic surfactant [13], but they seem to be degraded as shown in Fig.5, this degradation occurs as a result of break-up of the micelle microstructure due to high shear stresses that exceed critical stress. The decreasing in drag reduction can be also explained if we know that for anionic surfactant the spherical micelles usually aggregate into cylindrical micelles, which formed a network of interlaced rod-like elements and the aggregation forces of the surfactant molecules are overcome by the shear stress so the aggregates are broken down to small particles, which have little drag reduction ability.…”

Section: Resultsmentioning

confidence: 99%

Effect of SDBS on the drag reduction characteristics of polyacrylamide in a rotating disk apparatus

Bari

Yousif

Yaacob³

et al. 2015

IJBAS

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This paper focuses on the determination of the interaction between polymer (Polyacrylamide (PAM)) and surfactant (Sodium dod benzene sulfonate (SDBS)) as a drag reducer using Rotating Disk apparatus (RDA) at various concentrations (500, 700, 1000, 1500 and 2000) ppm individually and in the combined form under turbulent conditions at different rotation speed up to 3000 rpm, as well as studying their mechanisms as a drag reducer. The results show that the maximum percent drag reduction increases to (40, 41, 43, 45 and 48)% by using the combined additives of surfactant and polymer at the above concentrations respectively, with slower degradation and display drag reduction for a larger range of Reynolds numbers. The nano and micro particles formed from the combined PAA and SDBSA was studied using cryo-transmission electron microscopy (cryo-TEM) techniques. The images show the surrounding of polymer chain to the surfactant micelle to form an aggregate structure. A hexagonal crystalline form was suggested to describe the shape of the aggregate structure.

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Section: Resultsmentioning

confidence: 99%

Effect of SDBS on the drag reduction characteristics of polyacrylamide in a rotating disk apparatus

Bari

Yousif

Yaacob³

et al. 2015

IJBAS

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“…Suspensions of macroscopic fibers and surfactants are also known to be drag-reducing (Radin et al, 1975;Metzner, 1977;Shenoy, 1984;Lin and Zakin, 2001). Drag reduction in fiber suspensions and surfactants is much less and much more dramatic than in polymer systems, respectively.…”

Section: Chapter 7 Future Workmentioning

confidence: 99%

“…This is the so-called "polymer drag reduction" phenomenon, and was first observed experimentally in 1940s (Lumley, 1969;Virk, 1975;McComb, 1990;Graham, 2004). Since then, it has been found that many other types of additives, including rigid fibers (Lee et al, 1974;Radin et al, 1975;Metzner, 1977), wormy micelle-forming surfactants (Shenoy, 1984;Lin and Zakin, 2001) and even micro bubbles (L'vov et al, 2005;Ortiz-Villafuerte and Hassan, 2006) With these definitions, the laminar-turbulent transition can be represented on a Prandtlvon Karman plot, U avg /u τ vs. log Re τ , shown schematically in Fig. 4.…”

Section: Introductionmentioning

confidence: 99%

Polymer induced drag reduction in exact coherent structures of plane Poiseuille flow

Graham

2007

Physics of Fluids

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Nonlinear traveling waves that are precursors to laminar-turbulent transition and capture the main structures of the turbulent buffer layer have recently been found to exist in all the canonical parallel flow geometries. The present work examines the effect of polymer additives on these "exact coherent states" (ECS) in the plane Poiseuille geometry, using the FENE-P constitutive model for polymer solutions. In experiments with a given fluid, Reynolds and Weissenberg numbers are linearly related (i.e. Wi/Re = const).In this situation, we study the effects of viscoelasticity on velocity field and polymer stress field along some experimental paths, which represent different flow behaviors as Re (and Wi) increases. The changes to the velocity field for the viscoelastic nonlinear traveling waves qualitatively capture many of those experimentally observed in fully turbulent flows of polymer solutions at low to moderate levels of drag reduction: drag is reduced, streamwise velocity fluctuations increase, wall-normal and spanwise velocity fluctuations decrease. The mechanism underlying these observations is the suppression of streamwise vortices by the polymer forces exerted on the fluid. Specifically, at sufficiently high wall shear rates, viscoelasticity completely suppress these streamwise vortices in the near-wall region, as is found in experiments in the maximum drag reduction (MDR) regime. The mean shear stress balance for the nonlinear traveling waves show that Reynolds shear stress decreases and polymer stress increases monotonically with the increase of viscoelasticity, as are found in full turbulence. The study of the influence of the viscoelasticity on the turbulent kinetic energy and Reynolds stress budgets shows that as Re (and Wi) increases, there is a consistent decrease in the production, diffusion and dissipation of turbulent kinetic energy. The decrease in the velocity pressure gradient term leads to a redistribution of the turbulent kinetic energy among the streamwise, iii wall-normal and spanwise directions. The influence of the rheological parameters on the viscoelastic ECS is analyzed. It is found that the degree of drag reduction is determined primarily by the extensional viscosity and Weissenberg number. The optimum wavelength conditions under which the viscoelastic ECS first come into existence are also investigated. The wavelengths in streamwise and spanwise directions and the wallnormal extent of the ECS all increase monotonically with the increase of viscoelasticity, as is found in experiments. Examination of the parameter space (Re, Wi) in which ECS exist indicates that at least at the Reynolds number considered here, the transition behaviors from laminar to turbulent flow, from no drag reduction to drag reduction, and from moderate drag reduction to MDR can be connected to the birth, evolution and death of these ECS, respectively.In order to test the scenario that we infer from these results, we next implement direct numerical simulation (DNS), studying the transient and statistical...

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“…This turbulent drag reduction phenomenon implies that pipe flow containing these additives requires a lower pressure drop for a given flow rate (Rozenblit et al, 2006, Nguyen et al, 2006. The characteristics of such a dilute surfactant solution have been investigated in oil well fracturing operations (Ousterhout and Hall, 1961), increasing the output of the water jet during fire fighting (Fabula, 1971), in transportation of crude oil in the Alaska and Norwegian pipelines (Sellin and Ollis, 1980;Burger et al, 1980), sewage systems to prevent overflow during heavy rains (Sellin and Ollis, 1980), in water supply and irrigation systems (Sellin et al, 1982 a, b;Shenoy, 1984), hydraulic transportation of solid particle suspensions (Golda, 1986), and closed-circuit pumping installations (Choi et al, 2000;Suzuki et al, 2005). A similar application is the addition of polymers to oil being pumped from offshore platforms to shore facilities (Beaty et al, 1984).…”

Section: Introductionmentioning

confidence: 99%

Influence of Chemical Reagents on Rheological Properties of Fly Ash-Water Slurry at Varying Temperature Environment

Naik¹,

Mishra²,

Rao³

2011

CCGP

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About 70% of total electrical energy is generated from thermal power plants in India which in turn release about 160 Mt of fly ash as solid waste annually. Transportation and disposal of such a huge amount of fly ash is a major problem faced by the power plants. Presently fly ash is transported as lean slurry in pipe lines requiring about 80 to 85% of water with high energy input. A major impediment in high volume transportation of fly ash is its high specific gravity as compared to that of water. The objective of the present study was to evaluate the rheological characteristics of high concentration fly ash slurry with and without a chemical reagent at varying temperature environment to facilitate smooth flow of materials in the pipelines. Six different composition of fly ash slurry samples were considered for investigation. The main constituents of the slurry were fly ash, water, a cationic surfactant, and a counter-ion. Detailed rheological properties were determined using a cylindrical coaxial rotational rheometer at shear rates varying from 25s 21 to 1000s 21 for 40% solid concentration (by weight). Temperature was varied from 20uC to 40uC for all the shear rates investigated. Test results showed that all the slurries exhibited shearthinning behaviour in the presence of the surfactant. The influence of cationic tenside on drag reduction of fly ash slurry was also studied. The distinctive reduction of surface tension on colloidal dispersion characteristics of the fly ash slurry was observed in the presence of the tenside. It revealed that the slurry developed in the above manner has a potential to be transported through pipelines with minimal energy consumption.

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A review on drag reduction with special reference to micellar systems

Cited by 103 publications

References 208 publications

Effect of SDBS on the drag reduction characteristics of polyacrylamide in a rotating disk apparatus

Effect of SDBS on the drag reduction characteristics of polyacrylamide in a rotating disk apparatus

Polymer induced drag reduction in exact coherent structures of plane Poiseuille flow

Influence of Chemical Reagents on Rheological Properties of Fly Ash-Water Slurry at Varying Temperature Environment

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