Surfactant systems for drag reduction: Physico-chemical properties and rheological behaviour

The biaxial extensional characteristics of a cationic surfactant solution system showing an effective drag reduction in pipe flow have been studied by using two opposed nozzle devices. Aqueous solutions of cationic surfactant, oleylbishydroxyethylmethylammonium chloride, at the concentrations varied from 250 to 1,000 ppm with sodium salicylate, which ionized to counter-ion in an aqueous solution, of which molar ratio to surfactant was set at 1.5, were tested. Especially, time characteristics of extensional stress were focused in wide ranges of surfactant concentration and extensional rate. From the results, the apparent extensional viscosity is found to depend on the extensional rate and on the surfactant concentration. For the extensional rate dependency, the extensional viscosity behavior is classified into four regions. This characteristic is considered to be caused by the formation and the deformation of the surfactant rodlike micellar network structure. In each region, the build-up and relaxation times are not strongly affected by the concentration of the surfactant. On the other hand, the build-up time decreases with a gradient of -1 in a double logarithm plot to the extensional rate, while the relaxation time decreases weakly with the extensional rate. The former fact indicates the micellar network formation occurs due to the collision of surfactant micelles. It is also found that two relaxation processes exist for the extensional flow cases. The shorter or the longer relaxation time takes almost the same value as each value corresponding to that for the shear flow release condition. This indicates the network structure size formed in the biaxial extensional flow takes almost the same as that in the shear flow.

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“…This is caused by the deformation of shear induced state, SIS, reported by Orlendorf et al 15) at high shear rate. …”

Section: Extensional Viscosity and Extensional Stressmentioning

confidence: 92%

Biaxial Extensional Characteristics of Drag-Reducing Surfactant Solution

Nguyen

Ishihara

Suzuki

et al. 2005

J. Soc. Rheol., Jpn

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“…In the previous studies 15,23) , relationship between drag reduction effect and visco-elastic property of test fluids was discussed. PAA is visco-elastic fluid (shown in Figs. 3), and pressure drops are reduced by this visco-elastic property.…”

Section: Visco-elastic Propertymentioning

confidence: 99%

Flow Properties of Microbubble Mixtures and Complex Fluids Passing through Micro-Apertures

Ushida

Hasegawa

Sato

et al. 2016

J. Soc. Rheol., Jpn

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The pressure drops were measured for water, microbubble/water mixtures, and complex fluids (spherical micelle surfactant solution and polymer solution) in flows through micro-apertures (micro-orifices, circular pores, and hexagonal pores). For water, agreement between the resultant pressure drops and the predictions of the NavierStokes equation was obtained. For microbubble/water mixtures, drag reduction effect was suggested over a Reynolds number of about 1.0 × 10 1 in micro-orifice flows. Surfactant solutions exhibited the same results as microbubble/water mixtures. For polymer solutions, significant drag reduction was shown. Moreover, a drag reduction effect, which was independent of the used test fluids, was observed for Reynolds numbers over 1.0 × 10 1 in the flow through circular pores and hexagonal pores. To explain this phenomenon, the size effect, visco-elastic property, electric interaction, and interfacial tension are considered. The results suggest that electric interaction at the wall (interfacial tension) is a contributing factor. In addition, drag reduction rates were estimated. , who derived a mechanism for drag reduction by polymer additives based on elastic theory. Ogata et al. 19)have investigated the effect of surfactant solutions on the flow through a circular cylinder for Re ranging between 10 1 and 10 5 by measuring the drag coefficients and by flow visualizations.As summarized the above studies, channel flows (pipe flows, capillary flows, and rectangular channel flows) were investigated by using several types of fluids, and relationship between their rheological properties (elasticity and viscosity) and the drag reduction effect was reported for the complex fluids (dilute aqueous solutions of polymers and surfactants with wormlike micelles). Additionally, effects of volume fractions and particle diameters generated microbubbles were reported in microbubble drag reduction. However, the used characteristic length was more than 1 millimeter.Relative small size (< 1 mm) was limited. Moreover, spherical micelle surfactant solutions were not observed. On the other hand, drag reduction effect of microbubble mixtures, spherical micelle surfactant solutions, and polymer solutions in "capillary flows" was observed in our previous study 20) , which the diameter ranged from 110 μm to 0.75 mm. Also, it suggested pseudo-laminarization effect for the above test fluids. However, the flows through micron-sized apertures (example for orifice, slit, and pores) were limited. In this study, flows of water, microbubble/water mixtures, spherical micelle surfactant solution, and polymer solution passing through micron-sized apertures (micro-orifices, circular pores, and hexagonal pores) were investigated. Flow properties and the origin of drag reduction effects in the flows through microapertures are discussed by the results. EXPERIMENTAL PROCEDURE Test FluidsFour types of test fluids were used in this study. Deionized water (electric conductivity: 0.055 μS/cm; passed through a filter with pore size 5.0 μm befor...

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“…Ltd., Mumbai, India) was selected for its eco-friendly attributes. It is less susceptible to mechanical degradation compared to that of polymers (Qi et al, 2003) and also has known potential to positively influence turbulent flow with very small parts (Ohlendorf et al, 1986). It is also least affected by Ca and Na ions present in tap water (Kawaguchi et al, 1997;Li et al, 2008).…”

Section: Drag Reducing Reagentsmentioning

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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Surfactant systems for drag reduction: Physico-chemical properties and rheological behaviour

Cited by 291 publications

References 40 publications

Biaxial Extensional Characteristics of Drag-Reducing Surfactant Solution

Biaxial Extensional Characteristics of Drag-Reducing Surfactant Solution

Flow Properties of Microbubble Mixtures and Complex Fluids Passing through Micro-Apertures

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

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