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.

Drag Reduction of the Flow Past a Circular Cylinder in Surfactant Solution

2001 ◽  
Author(s):  
Satoshi Ogata ◽  
Keizo Watanabe
Keyword(s):  
Circular Cylinder ◽  
Drag Reduction ◽  
Sodium Salicylate ◽  
Tap Water ◽  
Pressure Coefficient ◽  
Surfactant Solution ◽  
Reduction Ratio ◽  
Number Range ◽  
Surfactant Solutions ◽  
Maximum Drag Reduction

Abstract The flow around a circular cylinder in surfactant solution was investigated experimentally by measurement of the pressure and velocity profiles in the Reynolds number range 6000 < Re < 50000. The test surfactant solutions were aqueous solutions of Ethoquad O/12 (Lion Co.) at concentrations of 50, 100 and 200 ppm, and sodium salicylate was added as a counterion. It was clarified that the pressure coefficient of surfactant solutions in the range of 10000 < Re < 50000 at the behind of the separation point was larger than that of tap water, and the separation angle increased with concentration of the surfactant solution. The velocity defect in surfactant solutions behind a circular cylinder was smaller than those in tap water. The drag coefficients of a circular cylinder in surfactant solutions were smaller than those of tap water in the range 10000 < Re < 50000, and no drag reduction occurred at Re = 6000. The drag reduction ratio increased with increasing concentration of surfactant solution. The maximum drag reduction ratio was approximately 35%.

G143 Study on the Heat Transfer Characteristics for Drag Reduction Surfactant Solution

2009 ◽  
Vol 2009 (0) ◽  
pp. 201-202
Author(s):  
Shogo Ozawa ◽  
Takuya Nishimura ◽  
Koji Matsumoto ◽  
Nobuyuki Takenaka ◽  
Katsumi Sugimoto
Keyword(s):  
Heat Transfer ◽  
Drag Reduction ◽  
Surfactant Solution ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics

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.

Flow and Heat Transfer of Microfoams in Horizontal Minichannels

2004 ◽  
Author(s):  
Howard Tseng ◽  
Laurent Pilon
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Mass Flow ◽  
Oil Recovery ◽  
High Speed ◽  
Surfactant Solution ◽  
Transfer Coefficients ◽  
Adiabatic Flow ◽  
Rectangular Channels ◽  
Fanning Friction Factor

Colloidal gas aphrons (CGA) consists of closely packed minute gas bubbles with diameter ranging from 10 to 100 microns. It is produced by stirring a surfactant solution at high speed in a fully baffled beaker. CGA can be used in various applications such as bioremediation, bioreactors, oil recovery, and fire fighting. This paper reports experimental data for (1) adiabatic flow and (2) convective heat transfer of CGA into five 1.58 × 0.76 mm2 mini-rectangular channels. First, it is shown that CGA is a shear thinning fluid. Correlation for the Fanning friction factor as a function of Reynolds number is compared with that of water and macrofoams. Then, the local temperature and heat transfer coefficient along the minichannels are reported as a function of the mass flow rates and imposed heat flux. The heat transfer coefficients for CGA appears to be constant and independent of mass flow rate and imposed heat flux as well known in the case of single phase laminar flow.

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.

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