Visualization of the Surfactant Solution Flow due to a Rotating Disk in a Cylindrical Casing

2003 ◽  
Vol 2003 (0) ◽  
pp. 173
Author(s):  
Mitsunori YOSHIDA ◽  
Motoyuki ITOH ◽  
Shinzi TAMANO ◽  
Kazuhiko YOKOTA
Keyword(s):  
Surfactant Solution ◽  
Rotating Disk ◽  
Solution Flow ◽  
Cylindrical Casing

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

2008 ◽  
Vol 130 (8) ◽  
Author(s):  
Shinji Tamano ◽  
Motoyuki Itoh ◽  
Mitsunori Yoshida ◽  
Kazuhiko Yokota
Keyword(s):  
Reynolds Number ◽  
Surfactant Solution ◽  
Rotating Disk ◽  
Swirling Flows ◽  
Visualization Technique ◽  
Constant Frequency ◽  
First Normal Stress Difference ◽  
Surfactant Solutions ◽  
Cylindrical Casing ◽  
Elasticity Number

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%.

scholarly journals Study on the Drag Reducing Channel Fluids by Experiments and DNS Using Giesekus Model

2014 ◽  
Vol 6 ◽  
pp. 175059 ◽  
Author(s):  
Weiguo Gu ◽  
Dezhong Wang ◽  
Yasuo Kawaguchi
Keyword(s):  
Shear Stress ◽  
Channel Flow ◽  
Mass Concentration ◽  
Reynolds Shear Stress ◽  
Surfactant Solution ◽  
Solution Flow ◽  
Velocity Fluctuations ◽  
Giesekus Model ◽  
Numerical Studies ◽  
Fluid Characteristics

Both experimental and numerical studies are simultaneously performed for fully developed water and surfactant solution channel flow. The comparison aims at the surfactant solution flow in experiment with mass concentration of 25 ppm at Re = 1000 and Giesekus model with Weissenberg numbers of 10 and 40 at Reτ = 150. Big differences are found between the experimental and DNS results by comparing the distributions of velocity fluctuations, Reynolds shear stress, and so on. Although large drag reduction appears in DNS, Giesekus model has some limitations in describing the fluid characteristics and viscoelasticity of the surfactant solution.

Spectral Analysis and Discussion on the Velocity Fluctuation in Drag Reducing Channel Flow by Surfactant Additives

2016 ◽  
Author(s):  
Yuichi Kaiho ◽  
Shumpei Hara ◽  
Takahiro Tsukahara ◽  
Yasuo Kawaguchi
Keyword(s):  
Channel Flow ◽  
Time Scale ◽  
Velocity Fluctuation ◽  
Surfactant Solution ◽  
Turbulent Velocity ◽  
Laser Doppler Velocimeter ◽  
Wall Region ◽  
Solution Flow ◽  
Velocity Fluctuations ◽  
Turbulent Velocity Fluctuation

It is known as the Toms effect that the wall friction coefficient is reduced by adding a small amount of polymer or surfactant into a water flow. In the drag-reducing flow, it is expected that a time scale of turbulent velocity fluctuation is changed by relaxation time due to viscoelasticity. In the present study, experimental analysis of the turbulent velocity fluctuation was performed with temporal characteristics in surfactant solution flow. The velocity fluctuations were measured by using a two-component laser Doppler velocimeter system on turbulent channel flow. And then, we performed statistical operation on those data and examined the time scale. From spectra analysis, it was found that very low frequency velocity fluctuations existed near the wall region in the surfactant solution flow. It was also revealed that the strong anisotropy occurred not only with the intensity but also with frequency distribution in turbulent velocity fluctuations. Moreover, the turbulence contributes nothing to the Reynolds shear stress and behaves as a wave motion. It was concluded that the turbulent eddies and viscoelasticity were two factors contributing to turbulent generation in the viscoelastic turbulent flow, with each factor having its own time scale.

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

2007 ◽  
Author(s):  
S. Tamano ◽  
M. Itoh ◽  
M. Yoshida ◽  
K. Yokota
Keyword(s):  
Reynolds Number ◽  
Surfactant Solution ◽  
Swirling Flows ◽  
Visualization Technique ◽  
Rotating Disc ◽  
Constant Frequency ◽  
First Normal Stress Difference ◽  
Surfactant Solutions ◽  
Aqueous Surfactant Solution ◽  
Cylindrical Casing

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%.

scholarly journals Flow of Aqueous Surfactant Solution due to a Rotating Disc in a Cylindrical Casing

2005 ◽  
Vol 71 (704) ◽  
pp. 1043-1050
Author(s):  
Motoyuki ITOH ◽  
Shinji TAMANO ◽  
Mitsunori YOSHIDA ◽  
Kazuhiko YOKOTA
Keyword(s):  
Surfactant Solution ◽  
Rotating Disc ◽  
Aqueous Surfactant Solution ◽  
Cylindrical Casing
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