Rheological Characteristics and Turbulent Friction Drag and Heat Transfer Reductions of a Very Dilute Cationic Surfactant Solution

2006 ◽  
Vol 128 (10) ◽  
pp. 977-983 ◽  
Author(s):  
Jinjia Wei ◽  
Yasuo Kawaguchi ◽  
Bo Yu ◽  
Ziping Feng
Keyword(s):  
Heat Transfer ◽  
Cationic Surfactant ◽  
Surfactant Solution ◽  
Viscosity Data ◽  
Fluid Temperature ◽  
Rheological Characteristics ◽  
Friction Drag ◽  
Rheological Characterization ◽  
Turbulent Friction ◽  
Surfactant Solutions

Turbulent friction drag and heat transfer reductions and rheological characteristics of a very dilute cationic surfactant solution, cetyltrimethyl ammonium chloride (CTAC)/sodium salicylate (NaSal) aqueous solution, were experimentally investigated at various temperatures. It was found that there existed a critical temperature above which drag and heat transfer reductions disappeared and shear viscosities rapidly dropped to that of water. It was surmised that drag and heat transfer reductions had a certain relationship with rheological characteristics and a rheological characterization of CTAC∕NaSal surfactant solutions was performed to clarify this relationship. The effects of Reynolds number and fluid temperature and concentration on drag and heat transfer reductions were qualitatively explained by analyzing the measured shear viscosity data at different shear rates and solution temperatures and concentrations. The Giesekus model was found to fit the measured shear viscosities reasonably well for different temperatures and concentrations of the surfactant solution and the model parameter values obtained by fitting were correlated with temperature at certain solution concentrations. From the correlation results, the temperature effect on viscoelasticity of surfactant solutions was analyzed to relate the rheological characteristics with drag and heat transfer reduction phenomena.

Surfactant Effects on Picloram Adsorption by Soils

Weed Science ◽  
1976 ◽  
Vol 24 (6) ◽  
pp. 549-552 ◽  
Author(s):  
J. D. Gaynor ◽  
V. V. Volk
Keyword(s):  
Organic Matter ◽  
Cationic Surfactant ◽  
Anionic Surfactant ◽  
Organic Matter Content ◽  
Clay Content ◽  
Surfactant Solution ◽  
Matter Content ◽  
Adsorption Sites ◽  
Surfactant Solutions ◽  
Extractable Al

The effects of soil organic matter, clay, extractable Al, cation exchange capacity, and pH on the adsorption of picloram (4-amino-3,5,6-trichloropicolinic acid) from aqueous and surfactant solutions were investigated. Linear adsorption isotherms for the soils were obtained with the Freundlich equation. Of the five soil properties investigated, Freundlich K values correlated with extractable Al and clay content. Picloram adsorption from aqueous solutions and from the non-ionic and anionic surfactant solutions was greater on the soils at pH 5 than at pH 7. The anionic surfactant competed with picloram for adsorption sites on the soils at pH 5. Picloram adsorption from solutions containing 0.1 and 1% cationic surfactant was greater than that from aqeuous and anionic and nonionic surfactant solutions. Picloram adsorption from the 10% cationic surfactant solution was similar on soils with pH 5 and 7 and increased with decreased organic matter content.

Bubble Growth in Surfactant Solutions

2010 ◽  
Author(s):  
G. Hetsroni ◽  
A. Mosyak
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Bubble Growth ◽  
High Speed ◽  
Surfactant Solution ◽  
Life Time ◽  
Channel Length ◽  
Gap Size ◽  
High Speed Video ◽  
Surfactant Solutions

The presence of surfactant additives in water was found to enhance significantly the boiling heat transfer. The objective of the present investigation was to compare the bubble growth in water to that of a surfactant solution with negligible environmental impact. The study was conducted to clarify the effect of the heat flux on the dynamics of bubble nucleation. The bubble growth under condition of pool boiling in water and surfactant solutions was studied using high speed video technique. The bubble generation was studied on a horizontal flat surface; where the natural roughness of the surface was used to produce the bubbles. At heat flux of q= 10 kW/m2 the life-time and the volume of bubble growth in surfactant solution did not differ significantly from those of water. The time behavior of the contact angle of bubble growing in surfactant solution is qualitatively similar to that of water. At a heat flux of q= 50 kW/m2, boiling in surfactant solution, when compared with that of pure water, was observed to be more vigorous. Surfactant promotes activation of nucleation sites; the bubbles appeared in a cluster mode; the life-time of each bubble in the cluster is shorter than that of a single water bubble. The detachment diameter of water bubble increases with increasing heat flux, whereas analysis of bubble growth in surfactant solution reveals the opposite effect: the detachment diameter of the bubble decreases with increasing heat flux. Natural convection boiling of water and surfactants at atmospheric pressure in narrow horizontal annular channels was studied experimentally in the range of Bond numbers Bo = 0.185–1.52. The flow pattern was visualized by high-speed video recording to identify the different regimes of boiling of water and surfactants. The channel length was 24mm and 36mm, the gap size was 0.45, 1.2, 2.2, and 3.7mm. The heat flux was in the range of 20–500 kW/m2, the concentration of surfactant solutions was varied from 10 to 600 ppm. For water boiling at Bond numbers Bo<1 the CHF in restricted space is lower than that in unconfined space. This effect increases with increasing the channel length. For water at Bond number Bo = 1.52, boiling can almost be considered as unconfined. Additive of surfactant led to enhancement of heat transfer compared to water boiling in the same gap size, however, this effect decreased with decreasing gap size. For the same gap size, CHF in surfactant solutions was significantly lower than that in water. Hysteresis was observed for boiling in degraded surfactant solutions.

Experimental Investigation of Thermal and Hydrodynamic Development Regions for Drag-Reducing Surfactant Solutions

1997 ◽  
Vol 119 (1) ◽  
pp. 80-88 ◽  
Author(s):  
K. Gasljevic ◽  
E. F. Matthys
Keyword(s):  
Heat Transfer ◽  
Polymer Solutions ◽  
Local Heat Transfer ◽  
Surfactant Solution ◽  
Local Heat ◽  
Velocity Profiles ◽  
Wire Mesh ◽  
Surfactant Solutions ◽  
Structure Degradation ◽  
Local Shear

The reductions in friction and heat transfer exhibited by a surfactant solution in the entry region of a circular pipe were measured and analyzed, with special attention paid to the relationship between the local heat transfer and friction. Two entrance configurations were used, a cone contraction and wire mesh plugs used as a device for velocity profile flattening. Both the simultaneous development of temperature and velocity profiles and the development of temperature profile with hydrodynamically predeveloped flow were studied. Interestingly, the local heat transfer measurements for surfactant solutions matched very well a correlation developed for polymer solutions, but for surfactants the development of the heat transfer and velocity profiles appear coupled, unlike what is thought to happen for polymer solutions. The development patterns appear to be independent of velocity and entrance type at low disturbance levels. At high disturbance levels, however, some striking changes in the fluid itself, likely due to temporary micellar structure degradation by high local shear stress in the inlet region, were observed as well, and quantified.

Rheological Characterization of Drag-Reducing Cationic Surfactant Solution: Shear and Elongational Viscosities of Dilute Solutions

2003 ◽  
Author(s):  
Yasuo Kawaguchi ◽  
Jinjia Wei ◽  
Bo Yu ◽  
Ziping Feng
Keyword(s):  
Cationic Surfactant ◽  
Surfactant Solution ◽  
Model Parameters ◽  
Rheological Characterization ◽  
Giesekus Model ◽  
Turbulent Drag ◽  
Different Temperatures ◽  
Cetyltrimethyl Ammonium ◽  
Parameter Values

Shear viscosities of one kind of turbulent drag-reducing cationic surfactant solution, Cetyltrimethyl ammonium chloride (CTAC)/Sodium salicylate (NaSal) aqueous solution, were experimentally investigated by use of a stress controlled Reometer. The concentration and temperature of the solution ranged from 50 to 200 ppm and 20 to 40°C, respectively. The Giesekus model was found to fit the measured shear viscosities well for different temperatures and concentrations of the surfactant solution and the model parameter values obtained by fitting were correlated with temperature at certain solution concentrations. The temperature was found to have a large influence on the viscoelasticity of the surfactant solution. By using the model parameters obtained from the correlations, 70 percent of the measured shear viscosities agreed with the prediction by the Giesekus model within ±27.3 percent. The elongational viscosities of CTAC/NaSal surfactant solution were also experimentally investigated by use of an oppositing jet Reometer. The measured data were lower than the prediction by the Giesekus model.

Synthesis of the Gold Nanocubes by Electrochemical Method with Surfactant Solution and Acetone Solvent Addition

2010 ◽  
Vol 434-435 ◽  
pp. 434-437 ◽  
Author(s):  
Kan Lin Chen ◽  
Chien Jung Huang ◽  
Pin Hsiang Chiu ◽  
Yeong Her Wang
Keyword(s):  
Cationic Surfactant ◽  
Electrochemical Method ◽  
Surfactant Solution ◽  
Hexadecyltrimethylammonium Bromide ◽  
Uniform Size ◽  
Growth Solution ◽  
Surfactant Solutions ◽  
Highly Uniform

Monodispersed gold nanocubes of highly uniform size were fabricated by a simple electrochemical method. The lengths of the edges of the gold nanocubes were about 30 nm. The growth solution was prepared from two cationic surfactant solutions as micelle templates with added acetone solvent. The primary surfactant was hexadecyltrimethylammonium bromide (CTAB) and the co-surfactant was tetradodecylammonium bromide (TTAB).

Influence of Counter-Ion Concentration on the Impinging Jet of Surfactant Solutions

2011 ◽  
Author(s):  
Nguyen Anh Tuan ◽  
Hiroshi Mizunuma
Keyword(s):  
Heat Transfer ◽  
Surfactant Solution ◽  
Impinging Jet ◽  
High Heat ◽  
Ion Concentration ◽  
Past Study ◽  
Surfactant Solutions ◽  
Counter Ion ◽  
High Heat Transfer ◽  
Wall Flow

An impinging jet is characterized by high heat transfer and thus is widely used in cooling and heating process in industry. On the other hand, surfactant solutions reduce pipe friction in turbulent flow and at the same time reduce heat transfer. In our past study, it was found that the surfactant solution with higher counter-ion concentration did not reduce the heat transfer in the impinging jet. This phenomenon suggested that the high heat transfer was characterized by high shear rate in impinging jet and not by turbulence. However, it has not yet been determined satisfactorily how the heat transfer is influenced by surfactant solutions in the impinging jet. Especially, the influence of the counter-ion concentration is important, because the counter-ion changes not only the heat transfer but also the rheology of the surfactant solutions. In this study, we visualized the impinging jet of the surfactant solutions, and the influence of the counter-ion was investigated. The results indicated that the wall flow was remarkably influenced by the counter-ion concentration in the impinging jet. In the case of the surfactant solution with equi-molar counter-ion, the induced wall flow was continued only near the stagnation point. By contrast, the solution with higher molar counter-ion induced the radial boundary layer flow on the wall similar to the water flow. This difference in flow would cause the different heat transfer, and the solution with higher molar counter-ion produces normal heat transfer. When comparing the visualized results of the impinging jet with the numerically simulated results, the qualitative agreement was not satisfactory for the surfactant solution with counter-ion of equi-molar concentration. The simulation used a Bingham model as the rheological equation, the constants of which were obtained from a cone and a plate rheometer. It was suggested that the surfactant solution indicated different rheological behavior in these viscometric flow and impinging jet.

Drag and Heat Transfer Reduction Phenomena of Drag-Reducing Surfactant Solutions in Straight and Helical Pipes

2006 ◽  
Vol 128 (8) ◽  
pp. 800-810 ◽  
Author(s):  
Wael I. A. Aly ◽  
Hideo Inaba ◽  
Naoto Haruki ◽  
Akihiko Horibe
Keyword(s):  
Heat Transfer ◽  
Drag Reduction ◽  
Surfactant Solution ◽  
Solution Concentration ◽  
Transfer Coefficients ◽  
Measured Concentration ◽  
Surfactant Solutions ◽  
Temperature Ranges ◽  
Experimental Findings ◽  
Flow Drag

Abstract Flow drag and heat transfer reduction phenomena of non-ionic aqueous surfactant solutions flowing in helical and straight pipes have been experimentally investigated at surfactant solution concentration range of 250-5000ppm and temperature range of 5-20°C. The helically coiled pipes have curvature ratios range of 0.018–0.045. Experimental findings indicate that the friction factors and the heat transfer coefficients of the surfactant solution in helical pipes are significantly higher than in a straight pipe and lower than Newtonian fluid flow like water through the same coils in the turbulent drag reduction region. Drag reduction and heat transfer reduction increase with an increase in surfactant solution concentration and temperature in the measured concentration and temperature ranges. On the other hand, they decrease with increasing of the curvature ratio. A set of empirical expressions for predicting the friction factor and the average Nusselt number for the surfactant solution’s flow through helical and straight pipes have been regressed based on the obtained data in the present experiments.

scholarly journals 0513 Drag reduction and heat transfer of cationic surfactant solutions

2009 ◽  
Vol 2009 (0) ◽  
pp. 235-236
Author(s):  
Takashi Saeki ◽  
Keiji Tokuhara ◽  
Toshio Matsumura
Keyword(s):  
Heat Transfer ◽  
Drag Reduction ◽  
Cationic Surfactant ◽  
Surfactant Solutions
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