Confined Swirling Flows of Aqueous Surfactant Solutions Due to a Rotating Disc in a Cylindrical Casing

Author(s):  
S. Tamano ◽  
M. Itoh ◽  
M. Yoshida ◽  
K. Yokota

In this study, confined swirling flows of an aqueous surfactant solution due to a rotating disc in a cylindrical casing were investigated using a sectional flow visualization technique and a two-component laser Doppler velocimetry (LDV) system. The concentrations of aqueous surfactant solutions (C14TASal) are 0.4, 0.8, and 1.2 wt%. Rheological properties such as a shear viscosity and a first normal stress difference of the surfactant solution were measured with a rheometer. The patterns of the secondary flow were classified using the Reynolds and elastic numbers. We revealed that the projection formed near the center of the rotating disc was moving up and down at a constant frequency for C14TASal 0.8 and 1.2 wt%, which has not been reported as far as we know. The effects of the Reynolds number, elastic number, and aspect ratio on the velocity profiles were clarified. It was also found that the region of rigid body rotation existed at the higher Reynolds number tested for C14TASal 0.4 wt%.

2008 ◽  
Vol 130 (8) ◽  
Author(s):  
Shinji Tamano ◽  
Motoyuki Itoh ◽  
Mitsunori Yoshida ◽  
Kazuhiko Yokota

In this study, confined swirling flows of an aqueous surfactant solution due to a rotating disk in a cylindrical casing were investigated using a sectional flow visualization technique and a two-component laser Doppler velocimetry system. The concentrations of aqueous surfactant solutions (C14TASal) are 0.4wt%, 0.8wt%, and 1.2wt%. Rheological properties such as shear viscosity and first normal stress difference of the surfactant solution were measured with a rheometer. The patterns of secondary flow were classified using the Reynolds and elasticity numbers. We revealed that the projection formed near the center of the rotating disk moved up and down at a constant frequency for C14TASal0.8wt% and 1.2wt%, which has not been reported as far as we know. The effects of the Reynolds number, elasticity number, and aspect ratio on the velocity profiles were clarified. It was also found that the region of rigid body rotation existed at the higher Reynolds number tested for C14TASal0.4wt%.


2005 ◽  
Vol 71 (704) ◽  
pp. 1043-1050
Author(s):  
Motoyuki ITOH ◽  
Shinji TAMANO ◽  
Mitsunori YOSHIDA ◽  
Kazuhiko YOKOTA

2004 ◽  
Vol 2004.2 (0) ◽  
pp. 171-172
Author(s):  
Wanheng LI ◽  
Motoyuki ITOH ◽  
Shinji TAMANO ◽  
Kazuhiko YOKOTA ◽  
Mitsunori YOSIDA

2004 ◽  
Author(s):  
Yoshihisa Osano ◽  
Satoshi Ogata ◽  
Keizo Watanabe

To clarify the effects of surfactant solutions on the drag coefficient of a circular cylinder, the flow past a circular cylinder was investigated in the Reynolds number range of 10 to 7,000 by measuring the drag and by visualizing flow. In addition, the flow pattern was simulated numerically to examine the effect of the viscoelasticity of the surfactant solution. Six cylinders with diameters between 2 and 20 mm were tested, and the ratio of length to diameter (l/d) was 12~48. The test surfactant solutions were aqueous solutions of oleyl-methyldihydroxyethyl ammonium chloride (trade name: Ethoquad O/12) in the concentration range of 50 to 200 ppm and sodium salicylate was added as a counterion. It was clarified that the drag coefficient of surfactant solutions increases comparing with that of tap water in the Reynolds number range of 1,000 < Re 3,000 and drag reduction occurs when Re > 3,000 for a cylinder diameter of 20 mm. The maximum drag reduction ratio was approximately 55% for 200 ppm solution at Re = 7,000. The flow visualization results showed that the drag of surfactant solutions increases because of the existence of the wide stagnant zone around the cylinder. This zone disappeared in the Reynolds number range in which drag reduction occurred. In addition, the width of the wake of surfactant solutions decreases compared with that of tap water, and the Ka´rma´n vortex street is not found. These effects seem to be due to the elasticity caused by the micellar network in surfactant solution.


Author(s):  
Satoshi Ogata ◽  
Keizo Watanabe ◽  
Yoshihisa Osano

To clarify the behavior of the drag coefficient of a circular cylinder in the intermediate Reynolds number range, the flow around a circular cylinder in surfactant solutions was investigated experimentally by measurement of the drag in the Reynolds number range of 3 × 102 to 7 × 103. The experiments were performed in a vertical re-circulating water tunnel. The drag coefficient was measured using an apparatus which could measure the drag acting on the circular cylinder directly. Five cylinders of diameter d = 5, 7, 10, 13 and 20 mm were tested, the ratios of length to diameter (l/d) were 12, 24 and 48. The test surfactant solutions were aqueous solutions of Ethoquad O/12 at concentrations of 50, 100 and 200 ppm, and sodium salicylate was added as a counterion. It was clarified that the drag coefficient of the cylinder in surfactant solutions increased comparing that in tap water in the Reynolds number lower approximately 103 < Re < 3 × 103. According to the increase of the Reynolds number, the drag coefficient decreased. When Reynolds number exceeded approximately 103 < Re < 3 × 103, the drag coefficient in surfactant decreased in comparison with that in tap water finally. In other ward, the drag reduction occurred in this Reynolds number range. The maximum drag reduction was about 55% for 200 ppm solution and 20mm diameter at Re ≅ 7 × 103. The value of the drag coefficient in surfactant solutions was dependent on not only (l/d) but also cylinder diameter. The drag coefficient increased with increasing cylinder diameter. The increase in the concentration of surfactant solution emphasized the characteristics of drag reduction and drag increase.


2004 ◽  
Author(s):  
Jinjia Wei ◽  
Fengchen Li ◽  
Bo Yu ◽  
Yasuo Kawaguchi

The swirling flows of water and CTAC (cetyltrimethyl ammonium chloride) surfactant solutions in an open cylindrical container with a rotating disc at the bottom were experimentally investigated by use of a double-pulsed PIV (particle image velocimetry) system. The mass concentrations of CTAC solutions were in the range of 50–1000 ppm, and the Reynolds number based on angular velocity, kinematic viscosity of water and radius of rotating disc was fixed at 4.3 × 104. The aspect ratio of the height of the liquid filled into the cylindrical vessel to the radius of the vessel was set to 1.0. The secondary flow patterns in the meridional plane and the tangential velocities were obtained. The flow pattern in the meridional plane for water at the present high Reynolds number differed greatly from that at low Reynolds numbers, and an inertia-driven vortex was pushed to the corner between the free surface and the cylindrical wall by a counter-rotating vortex caused by vortex breakdown. For the 1000-ppm surfactant solution flow, the inertia-driven vortex located at the corner between the bottom and the cylindrical wall whereas an elasticity-driven reverse vortex governed the majority of the flow field. The radial distributions of the time-averaged tangential velocities also differed for water and surfactant solutions. The rotation of the fluid caused a deformation of the free surface with a dip at the center. The dip was largest for the water case and decreased with increasing surfactant concentration.


SPE Journal ◽  
2013 ◽  
Vol 18 (05) ◽  
pp. 818-828 ◽  
Author(s):  
M. Hosein Kalaei ◽  
Don W. Green ◽  
G. Paul Willhite

Summary Wettability modification of solid rocks with surfactants is an important process and has the potential to recover oil from reservoirs. When wettability is altered by use of surfactant solutions, capillary pressure, relative permeabilities, and residual oil saturations change wherever the porous rock is contacted by the surfactant. In this study, a mechanistic model is described in which wettability alteration is simulated by a new empirical correlation of the contact angle with surfactant concentration developed from experimental data. This model was tested against results from experimental tests in which oil was displaced from oil-wet cores by imbibition of surfactant solutions. Quantitative agreement between the simulation results of oil displacement and experimental data from the literature was obtained. Simulation of the imbibition of surfactant solution in laboratory-scale cores with the new model demonstrated that wettability alteration is a dynamic process, which plays a significant role in history matching and prediction of oil recovery from oil-wet porous media. In these simulations, the gravity force was the primary cause of the surfactant-solution invasion of the core that changed the rock wettability toward a less oil-wet state.


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