The flow behavior of fiber suspensions in Newtonian fluids and polymer solutions.

1986 ◽  
Vol 25 (3) ◽  
pp. 246-256 ◽  
Author(s):  
S. Goto ◽  
H. Nagazono ◽  
H. Kato
Keyword(s):  
Polymer Solutions ◽  
Flow Behavior ◽  
Newtonian Fluids ◽  
Fiber Suspensions

The flow behavior of fiber suspensions in Newtonian fluids and polymer solutions.

1986 ◽  
Vol 25 (2) ◽  
pp. 119-129 ◽  
Author(s):  
S. Goto ◽  
H. Nagazono ◽  
H. Kato
Keyword(s):  
Polymer Solutions ◽  
Flow Behavior ◽  
Newtonian Fluids ◽  
Fiber Suspensions

Drag Reduction in Laminar Flow Between Two Vertical Coaxial Cylinders

1999 ◽  
Vol 121 (3) ◽  
pp. 541-547 ◽  
Author(s):  
Keizo Watanabe ◽  
Takashi Akino
Keyword(s):  
Drag Reduction ◽  
Polymer Solutions ◽  
Flow Behavior ◽  
Acrylic Resin ◽  
Coaxial Cylinder ◽  
Newtonian Fluids ◽  
Basic Material ◽  
Water Repellent ◽  
Coaxial Cylinders ◽  
Moment Coefficient

Laminar drag reduction has been shown for the flow of a Newtonian fluid in the space between two vertical coaxial cylinders. Experiments were carried out to measure the torque of a bob with a highly water-repellent wall to clarify the effect of the contact surface of the bob on the flow behavior. The basic material of the highly water-repellent wall is fluorine alkane modified acrylic resin with added hydrophobic silica, and the contact angle of the wall is about 150 degree. The radius rations of the bob were 0.932 and 0.676. Test fluids were Newtonian aqueous solutions of 60, 70, and 80 wt% glycerin and polymer solutions. The maximum drag reduction ratio was about 12% for 80 wt% glycerin solution at a radius ratio of 0.932. The moment coefficient of the coaxial cylinder in Newtonian fluids was analyzed for fluid slip, and it was shown that the analytical results agreed well with the experimental data. For the case of non-Newtonian fluids, the fluid slip velocity of polymer solutions is not proportional to the shear stress and the relationship is approximated by power-law equations.

scholarly journals Breakup Dynamics of Semi-dilute Polymer Solutions in a Microfluidic Flow-focusing Device

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 406
Author(s):  
Chun-Dong Xue ◽  
Xiao-Dong Chen ◽  
Yong-Jiang Li ◽  
Guo-Qing Hu ◽  
Tun Cao ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Polymer Solutions ◽  
Newtonian Fluids ◽  
Droplet Microfluidics ◽  
Droplet Generation ◽  
Flow Focusing ◽  
Polymeric Fluids ◽  
Practical Applications ◽  
Dilute Polymer Solutions ◽  
Microfluidic Flow

Droplet microfluidics involving non-Newtonian fluids is of great importance in both fundamental mechanisms and practical applications. In the present study, breakup dynamics in droplet generation of semi-dilute polymer solutions in a microfluidic flow-focusing device were experimentally investigated. We found that the filament thinning experiences a transition from a flow-driven to a capillary-driven regime, analogous to that of purely elastic fluids, while the highly elevated viscosity and complex network structures in the semi-dilute polymer solutions induce the breakup stages with a smaller power-law exponent and extensional relaxation time. It is elucidated that the elevated viscosity of the semi-dilute solution decelerates filament thinning in the flow-driven regime and the incomplete stretch of polymer molecules results in the smaller extensional relaxation time in the capillary-driven regime. These results extend the understanding of breakup dynamics in droplet generation of non-Newtonian fluids and provide guidance for microfluidic synthesis applications involving dense polymeric fluids.

Forming Process of Taylor Vortex Flow of Polymer Solutions

2004 ◽  
Author(s):  
Shu Sumio ◽  
Keizo Watanabe ◽  
Satoshi Ogata
Keyword(s):  
Reynolds Number ◽  
Flow Visualization ◽  
Vortex Flow ◽  
Polymer Solutions ◽  
Newtonian Fluids ◽  
Experimental Result ◽  
Taylor Vortex ◽  
Number Range ◽  
Primary Mode ◽  
Taylor Vortex Flow

The laser-induced fluorescence (LIF) technique carried out the flow visualization for the formation of Taylor vortex, which occurred in the gap between the two coaxial cylinders. The test fluids were tap water and glycerin 60wt% solution as Newtonian fluids. Polyacrilamide (SeparanAP-30) solutions in the concentration range of 10 ppm to 1000 ppm and polyethylene-oxide (PEO15) solutions in the range of 20 ppm to 1000 ppm were tested as non-Newtonian fluids, respectively. The Reynolds number range was 80 < Re < 4.0 × 103 in the experiment. The rotating inner cylinder was accelerated under the slow condition (dRe*/ dt ≤ 1 min−1) in order to obtain a Taylor vortex flow of the stable primary mode. Flow visualization results showed that the Go¨rtler vortices of half the number of Taylor cells occurred in the gap when Taylor vortex flow of the primary mode was formed. In addition, the critical Reynolds number of the polymer solutions case, which Taylor vortices occur, because the generation of the Go¨rtler vortices was retarded. At the higher concentration of the polymer solutions, this effect became remarkable. Measurements of steady-state Taylor cells showed that the upper and the lower cells of polymer solutions became larger in wavelength than that of the Newtonian fluids. The Taylor vortex flow of non-Newtonian fluids was analyzed and the result of the Giesekus model agreed with the experimental result.

Flow of Oil-in-Water Emulsions Through Tubes and Porous Media

1979 ◽  
Vol 19 (06) ◽  
pp. 369-377 ◽  
Author(s):  
D.A. Alvarado ◽  
S.S. Marsden
Keyword(s):  
Porous Media ◽  
Crude Oil ◽  
Capillary Tube ◽  
Flow Behavior ◽  
Oil Field ◽  
Newtonian Fluids ◽  
Capillary Tubes ◽  
The Past ◽  
Oil In Water ◽  
Physical Laws

Abstract The flow of oil-in-water macroemulsions through both porous media and capillary tubes has been studied experimentally and described mathematically. Macroemulsions are those emulsions with most of their droplet diameters greater than I AM, which is the same order of magnitude as the pore constrictions. The emulsions were pumped with a positive displacement pump through several porous media and capillary tubes connected in series. The rheological behavior of macroemulsions with oil concentrations ranging from 10 to 70 vol% was obtained using capillary tube data. Emulsions with oil concentrations less than 50% behaved like Newtonian fluids, white those with concentrations greater than 50% behaved like pseudoplastic fluids. Viscoelastic effects were not observed for these fluids. A correlation, which uses both capillary and core flow data, was developed for describing the flow of non-Newtonian macroemulsions through porous media. This led to a general equation that reduced to Darcy's law for Newtonian fluids. The average relative error found when applying the method of correlation was +/- 4 %. Introduction The subject of emulsions is a broad field that includes many instances of application in industry. We are interested mainly in one specific area of application here - the oil industry. The study of emulsions has received considerable attention in petroleum research laboratories during the past 15 petroleum research laboratories during the past 15 years. The development of new methods of secondary recovery and the potential application of crude oil transportation through pipelines as stable emulsions have increased the number of research programs dealing with emulsions. programs dealing with emulsions. Macroemulsions, or ordinary emulsions, are dispersions of one liquid within another liquid. third component in an emulsion is the emulsifying agent or emulsifier, which has two principal functions:to decrease the interfacial tension between the liquids, thereby enabling easier formation of the greatly extended interface, andto stabilize the dispersed phase against coalescence once it is formed. With water or brine as one of the liquids, two types of emulsions are possible - oil-in-water (O/W) and water-in-oil (W/O) emulsions. Note that most of worlds's crude oil is produced in emulsion form. These emulsions are generally water-in-crude oil emulsions, which are more viscous than either of their constituents. Since we are interested only in maximum economical oil production, it is a common practice to separate emulsions production, it is a common practice to separate emulsions into their components, thereby obtaining reduced viscosity. This is accomplished in the oil field by using chemical and heat treatments. In contrast to W/O emulsions, O/W emulsions have lower viscosities than their oil constituent. This was considered by some investigators during the development of systems for producing and transporting crude oil as O/W emulsions. During the last decade or so, a number of new secondary oil recovery processes have been developed. These methods include the use of high-viscosity emulsions to displace oil, the use of emulsion slugs between the displacing fluid (water) and the displaced fluid (Oil), and controlled viscosity microemulsions. We see that, for an engineer to describe properly the flow behavior of emulsions in both pipelines and reservoirs, he must know the properties of emulsions and the physical laws properties of emulsions and the physical laws controlling their flow through tubes and porous media. The purpose of this research was to study the flow of O/W macroemulsions through both porous media and capillary tubes. The rheological characteristics of emulsions were analyzed by using capillary viscometers. SPEJ P. 369

A comparison of numerical methods for non-Newtonian fluid flows in a sudden expansion

2016 ◽  
Vol 27 (12) ◽  
pp. 1650139 ◽  
Author(s):  
G.Di Ilio ◽  
D. Chiappini ◽  
G. Bella
Keyword(s):  
Computational Methods ◽  
Numerical Study ◽  
Flow Behavior ◽  
Fluid Flows ◽  
Newtonian Fluids ◽  
Sudden Expansion ◽  
Complex Flows ◽  
Symmetric Channel ◽  
Runge Kutta Method ◽  
Boltzmann Method

A numerical study on incompressible laminar flow in symmetric channel with sudden expansion is conducted. In this work, Newtonian and non-Newtonian fluids are considered, where non-Newtonian fluids are described by the power-law model. Three different computational methods are employed, namely a semi-implicit Chorin projection method (SICPM), an explicit algorithm based on fourth-order Runge–Kutta method (ERKM) and a Lattice Boltzmann method (LBM). The aim of the work is to investigate on the capabilities of the LBM for the solution of complex flows through the comparison with traditional computational methods. In the range of Reynolds number investigated, excellent agreement with the literature results is found. In particular, the LBM is found to be accurate in the prediction of the fluid flow behavior for the problem under consideration.

scholarly journals Investigation of Non-Newtonian Fluids Flow Behavior in A Double Step Expansion Channel: Part 2

2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Ahmed A. Ouda ◽  
Khudheyer S. Mushatet ◽  
Qais A. Rishack
Keyword(s):  
Flow Behavior ◽  
Newtonian Fluids ◽  
Double Step

scholarly journals A New Viscosity Constitutive Model for Generalized Newtonian Fluids Using Theory of Micropolar Continuum

2020 ◽  
pp. 120-134
Author(s):  
Muhammad Sabeel Khan
Keyword(s):  
Constitutive Model ◽  
Flow Behavior ◽  
Constitutive Relations ◽  
Shear Thickening ◽  
Blood Rheology ◽  
Newtonian Fluids ◽  
Model Parameters ◽  
Micropolar Continuum ◽  
Generalized Newtonian Fluids ◽  
Contour Plots

In this paper, a new viscosity constitutive relation for the analysis of generalized Newtonian fluids is presented and analyzed. The theory of micropolar continuum is considered for the derivation of constitutive relations where the kinematics at the macroscopic level leads to incorporate the micro-rotational effects in existing rheology of Carreau Yasuda model. It provides a more realistic approach to analyze the flow behavior of generalized Newtonian fluids. To the best of author’s knowledge such generalization of the existing rheology of Carreau-Yasuda is not present in literature. In order to show the effects of micro-rotations on the viscosity of generalized fluids, different computational experiments are performed using finite volume method (FVM). The method is implemented and validated for accuracy by comparison with existing literature in the limiting case through graphs and tables and a good agreement is achieved. It is observed that with the increase of micro-rotations the shear thinning phenomena slower down whereas the shear thickening is enhanced. Moreover, the effects of various model parameters on horizontal and vertical velocities as well as on boundary layer thickness are shown through graphs and contour plots It is worth mentioning that the proposed constitutive model can be utilized to analyze the generalized Newtonian fluids and has wider applications in blood rheology.

scholarly journals Investigation of Surfactant-Polymer Interactions Using Rheology and Surface Tension Measurements

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2302 ◽  
Author(s):  
Jia Yang ◽  
Rajinder Pal
Keyword(s):  
Surface Tension ◽  
Polymer Solutions ◽  
Flow Behavior ◽  
Polymer Concentration ◽  
Critical Aggregation Concentration ◽  
Ionic Surfactant ◽  
Marginal Effect ◽  
Anionic Polymer ◽  
Flow Behavior Index ◽  
Drag Reducing Polymer

The interactions between surfactants and a drag-reducing polymer were investigated at a low polymer concentration of 500 ppm, using measurements of the rheology and surface activity of surfactant-polymer solutions. A well-known drag-reducing polymer (anionic sodium carboxymethyl cellulose) and five different surfactants (two anionic, two non-ionic, and one zwitterionic) were selected for the interaction studies. The surfactant-polymer solutions were shear thinning in nature, and they followed the power law model. The interaction between the surfactant and polymer had a strong effect on the consistency index of the solution and a marginal effect on the flow behavior index. The surface tension versus surfactant concentration plots were interpreted in terms of the interactions between surfactant and polymer. The critical aggregation concentration (CAC) of the surfactant was estimated based on the surface tension and rheological data. The CAC values of the same charge surfactants as that of the polymer were found to be significantly higher than other combinations of surfactant and polymer, such as non-ionic surfactant/anionic polymer, and zwitterionic surfactant/anionic polymer.

Power Consumption of Polymer Solutions in a Stirred Vessel Powered by an Hyperboloid Impeller

2001 ◽  
Author(s):  
Adélio S. Cavadas ◽  
Fernando T. Pinho
Keyword(s):  
Power Consumption ◽  
Aqueous Solutions ◽  
Xanthan Gum ◽  
Polymer Solutions ◽  
Reynolds Numbers ◽  
Newtonian Fluids ◽  
Solution Flow ◽  
Stirred Vessel ◽  
Concentrated Aqueous Solutions ◽  
Rushton Turbine

Abstract Measurements of power consumption in stirred vessel flows powered by a Rushton and an hyperboloid impeller were carried out. The fluids were aqueous solutions of tylose, CMC and xanthan gum at weight concentrations ranging from 0.1% to 0.6% and also included Newtonian fluids. For the Rushton turbine flows the addition of polymer increased the Newton number by about 13–20% at Reynolds numbers in the range 1,000–3,000, whereas with the hyperboloid impeller the Newton number decreased about 13%. This decrease was especially noticeable for the CMC solutions and was absent from the 0.2% tylose solution flow. Concentrated aqueous solutions of CMC (5.2%) and XG (3.6%) were also produced to determine the characteristic impeller parameter k for the hyperboloid, following the procedure of Metzner and Otto (1957) which was found to be 48 ±16.

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