Effect of variations in counterion to surfactant ratio on rheology and microstructures of drag reducing cationic surfactant systems

An experimental study has been performed in order to investigate the optimum rheological characteristics for a technique of heat transfer augmentation in a cavity between ribs mounted in parallel plates. The rheological characteristics of visco-elastic fluid were changed by controling the molar ratio of counter-ion to a cationic surfactant. Flow visualization experiments and pressure loss measurements were conducted in the range of solvent Reynolds number from 100 to 2,500 and in the range of molar ratio from 0.50 to 10. Under this condition, the zoro-shear Reynolds number and the Weissenberg number ranged from 2.01 to 120 and from 1.94 × 10 -2 to 9.15, respectively.From the results, flow penetration into the cavity occurred in the cases from 1.5 to 5.0 of molar ratio of counter-ions. However, the pressure loss became large in the cases when the remarkable Barus effect can be observed. On the other hand, the pressure loss became almost the same as that of water in the case when the molar ratio of counter-ions was set at 5.0. From this, it was concluded that the optimum fluid for the heat transfer augmentation in a cavity is required to have suitable elasticity and low viscosity as the molar ratio of counter-ions is set around 5.0.

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“…Lu et al 12) on the relaxation time indicated the surfactant system shows a multi-mode relaxation behaviour.…”

Section: Rheological Characteristicsmentioning

confidence: 99%

Effects of the Molar Ratio of Counter-Ions on Flow Characteristics of Surfactant Solutions Sweeping Cavities

Sato

Suzuki

Hidema

et al. 2016

J. Soc. Rheol., Jpn

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“…(DR) Gyr, Bewersdorff 16) (Cryo TEM) ODMAO 17) DR (SIS) ODMAO C = 50, 100 500 750, 1000 ppm T ≈ 10 20 30 40 ºC AROMOX 1 100 % C = 500 ppm 3 DR 13) 3. t w U m (Fig. 11 ( Fig.…”

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confidence: 99%

Effects of Degradation on Drag Reduction in Turbulent Pipe Flow of Nonionic Surfactant Aqueous Solutions

Tamano

Miyagawa

Morinishi

et al. 2012

J. Soc. Rheol., Jpn

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We investigated effects of solution concentration C, solution temperature T, and degradation on drag reduction (DR) of nonionic surfactant aqueous solutions, which were non-toxic and biodegradable, by measuring the pressure drop and flow rate in the circuit pipe flow with the inner diameter of 25.1 mm. The maximum drag reduction ratio DR max increased from about 70 % to 80 % with increasing from C = 50 to 1000 ppm at T ≈ 20 ºC. The DR max at C = 100 ppm was independent of the solution temperature T from 10 to 40 ºC, while the region of Reynolds number at the large DR (> 60 %) was dependent on T. The degradation property strongly depended on whether the Reynolds number was smaller or larger than the critical Reynolds number, at which the DR was maximum. The drag-reducing effects obtained here were discussed as taking into account the strength of the shear thickening observed in the plot of shear viscosity vs. shear rate, which was measured by the homemade capillary viscometer.

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“…9, and then the relaxation behavior is analyzed by using two relaxation times fitting as follows. 18) for the case of shear relaxation. Figure 10 shows …”

Section: Time Characteristics Of Extensional Stressmentioning

confidence: 99%

Biaxial Extensional Characteristics of Drag-Reducing Surfactant Solution

Nguyen

Ishihara

Suzuki

et al. 2005

J. Soc. Rheol., Jpn

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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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Effect of variations in counterion to surfactant ratio on rheology and microstructures of drag reducing cationic surfactant systems

Cited by 69 publications

References 25 publications

Effects of the Molar Ratio of Counter-Ions on Flow Characteristics of Surfactant Solutions Sweeping Cavities

Effects of the Molar Ratio of Counter-Ions on Flow Characteristics of Surfactant Solutions Sweeping Cavities

Effects of Degradation on Drag Reduction in Turbulent Pipe Flow of Nonionic Surfactant Aqueous Solutions

Biaxial Extensional Characteristics of Drag-Reducing Surfactant Solution

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