Flow of Yield Power Law Fluids in Horizontal Pipes-Flow Field Characterization Using Particle Image Velocimetry Technique

2021 ◽  
Author(s):  
Yanxin (Sussi) Sun ◽  
Abdulla Abou-Kassem ◽  
Majid Bizhani ◽  
Ergun Kuru
Keyword(s):  
Experimental Study ◽  
Flow Field ◽  
Velocity Profile ◽  
Yield Stress ◽  
Power Law ◽  
Pipe Flow ◽  
Hydrodynamic Behaviour ◽  
Yield Stress Fluids ◽  
Power Law Fluids ◽  
Flow Field Characteristics

Abstract Yield Power Law (YPL) rheological model is commonly used to describe the pipe and annular flow of drilling fluids. However, the hydrodynamic behaviour of fluids with yield stress are difficult to predict because they exhibit an inherent plug (solid like) region where the velocity gradient is zero. Moreover, it is not easy to identify the transition between this solid like and liquid regions. Theoretical studies have been conducted in the past to describe YPL fluid flow in pipes and annuli. As a result, several models have been proposed for determining flow field characteristics (e.g. velocity profile, plug width, etc.) and frictional pressure losses. However, most of these models have been validated by limited experimental and/or field data. Similar future modeling studies may benefit from more data collected under controlled experimental conditions. Therefore, we have conducted an experimental study to investigate the hydrodynamic behaviour of yield stress fluids under laminar pipe flow conditions and the results are presented in this paper. Water-based Yield Power Law fluids were prepared by using Carbopol® 940, a synthetic high-molecular-weight polyacrylic acid-based cross-linked polymer. Fluids with yield stresses varying from 0.75 Pa (1.56 lb/100 ft2) to 4.37 Pa (9.13 lb/100 ft2) were obtained by using Carbopol concentrations changing from 0.060% w/w to 0.073% w/w. A 9m long horizontal pipeline with, 95 mm diameter (ID) was used for the experiments. Reynolds number range varying from 97 to 1268 confirmed that all flow field characteristics measurements of YPL fluids were conducted under laminar flow regimes. Experimental study provided detailed information about pipe flow characteristics of yield stress fluids, including full annular velocity profile, near wall velocity profile, wall slip velocity and the plug region thickness. The study was concluded by comparing experimental results (i.e. full velocity profile, frictional pressure loss, and plug width) to predictions of models presented in the literature. Practical implications of the results have also been discussed by considering the hydraulic design of some practical field operations such as hole cleaning.

Experimental study and numerical modeling of mixing by air injection in yield stress fluids using the OpenFOAM software

AIChE Journal ◽  
2021 ◽  
Author(s):  
Ali Hojeij ◽  
Laurent Jossic ◽  
Philippe Séchet ◽  
Cyrille Bonamy ◽  
Albert Magnin ◽  
...  
Keyword(s):  
Experimental Study ◽  
Numerical Modeling ◽  
Yield Stress ◽  
Air Injection ◽  
Yield Stress Fluids

scholarly journals Pipe rheology of microfibrillated cellulose suspensions

Cellulose ◽  
2019 ◽  
Vol 27 (1) ◽  
pp. 141-156 ◽  
Author(s):  
Tuomas Turpeinen ◽  
Ari Jäsberg ◽  
Sanna Haavisto ◽  
Johanna Liukkonen ◽  
Juha Salmela ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Yield Stress ◽  
Power Law ◽  
Slip Flow ◽  
Microfibrillated Cellulose ◽  
Flow Index ◽  
Shear Rheology ◽  
Power Law Fluids ◽  
Wall Shear

Abstract The shear rheology of two mechanically manufactured microfibrillated cellulose (MFC) suspensions was studied in a consistency range of 0.2–2.0% with a pipe rheometer combined with ultrasound velocity profiling. The MFC suspensions behaved at all consistencies as shear thinning power law fluids. Despite their significantly different particle size, the viscous behavior of the suspensions was quantitatively similar. For both suspensions, the dependence of yield stress and the consistency index on consistency was a power law with an exponent of 2.4, similar to some pulp suspensions. The dependence of flow index on consistency was also a power law, with an exponent of − 0.36. The slip flow was very strong for both MFCs and contributed up to 95% to the flow rate. When wall shear stress exceeded two times the yield stress, slip flow caused drag reduction with consistencies higher than 0.8%. When inspecting the slip velocities of both suspensions as a function of wall shear stress scaled with the yield stress, a good data collapse was obtained. The observed similarities in the shear rheology of both the MFC suspensions and the similar behavior of some pulp fiber suspensions suggests that the shear rheology of MFC suspensions might be more universal than has previously been realized.

Settling behavior of non-spherical particles in power-law fluids: Experimental study and model development

Particuology ◽  
2019 ◽  
Vol 46 ◽  
pp. 30-39 ◽  
Author(s):  
Zhengming Xu ◽  
Xianzhi Song ◽  
Gensheng Li ◽  
Zhaoyu Pang ◽  
Zhaopeng Zhu
Keyword(s):  
Experimental Study ◽  
Power Law ◽  
Model Development ◽  
Spherical Particles ◽  
Power Law Fluids ◽  
Settling Behavior

On strong blowing into an incompressible airstream

1973 ◽  
Vol 60 (2) ◽  
pp. 241-255 ◽  
Author(s):  
F. T. Smith
Keyword(s):  
Experimental Study ◽  
Flow Field ◽  
Velocity Profile ◽  
Air Injection ◽  
Relative Mass ◽  
Pressure Measurements ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Strong Injection ◽  
Steady Laminar

An experimental study of distributed air-injection from a porous section of a flat plate into a uniform incompressible airflow is described. The relative mass flow rates of the injection varied between 0·008 and 0·053 (strong injection) and the blowing was fairly uniformly distributed. In the resulting flow field, which was predominantly laminar except near the dividing streamline, where unsteadiness prevailed, velocity profile and pressure measurements were taken and the position of the dividing streamline thereby estimated. Overall the results agree fairly well with the steady laminar theory for strong normal blowing, outlined in §2, although for the strongest blow some signs of separation some way upstream of the blow are apparent.

Pipe Flow Measurements of a Transparent Non-Newtonian Slurry

1989 ◽  
Vol 111 (3) ◽  
pp. 331-336 ◽  
Author(s):  
J. T. Park ◽  
R. J. Mannheimer ◽  
T. A. Grimley ◽  
T. B. Morrow
Keyword(s):  
Velocity Profile ◽  
Newtonian Fluid ◽  
Power Law ◽  
Pipe Flow ◽  
Large Scale ◽  
Longitudinal Velocity ◽  
Tangential Velocity ◽  
Turbulent Pipe Flow ◽  
Laser Doppler Velocimeter ◽  
Flow Measurements

An experimental description of the flow structure of non-Newtonian slurries in the laminar, transitional, and full turbulent pipe flow regimes is the primary objective of this research. Experiments were conducted in a large-scale pipe slurry flow facility with an inside pipe diameter of 51 mm. The transparent slurry formulated for these experiments from silica, mineral oil, and Stoddard solvent exhibited a yield-power-law behavior from concentric-cylinder viscometer measurements. The velocity profile for laminar flow from laser Doppler velocimeter (LDV) measurements had a central plug flow region, and it was in agreement with theory. The range of the transition region was narrower than that for a Newtonian fluid. The mean velocity profile for turbulent flow was close to a 1/7 power-law velocity profile. The rms longitudinal velocity profile was also similar to a classical turbulent pipe flow experiment for a Newtonian fluid; however, the rms tangential velocity profile was significantly different.

Friction Coefficients for Bingham and Power-Law Fluids in Abrupt Contractions and Expansions

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Sergio L. D. Kfuri ◽  
Edson J. Soares ◽  
Roney L. Thompson ◽  
Renato N. Siqueira
Keyword(s):  
Reynolds Number ◽  
Yield Stress ◽  
Power Law ◽  
Reynolds Numbers ◽  
Newtonian Fluids ◽  
Rheological Parameters ◽  
Friction Coefficients ◽  
K Value ◽  
Power Law Fluids ◽  
Pipeline Systems

Industrial processes with non-Newtonian fluids are common in many segments such as petroleum, cosmetic, and food industries. Slurries, emulsions, and gas–liquid dispersions are some examples with industrial relevance. When a fluid flows in a pipe system, pressure losses are always present. For Newtonian fluids, a quite reasonable understanding of this phenomenon was already achieved and is available in the literature. The same cannot be stated for non-Newtonian fluids owing to their complex characteristics, such as pseudoplasticity, viscoplasticity, elasticity, and thixotropy. The understanding of the influence of these characteristics on flow behavior is very important in order to design efficient pipeline systems. The design of such systems requires the estimation of the pressure drop due to friction effects. However, there are few works regarding friction losses for non-Newtonian fluids in pipeline systems, making this task a difficult one. In this study, two classes of fluids are investigated and compared with the Newtonian results. The first category of fluids are the ones that exhibits pseudoplastic behavior and can be modeled as a power-law fluid, and the second category are the ones that possesses a yield stress and can be modeled as a Bingham fluid. Polyflow was used to compute the friction losses in both abrupt contractions and expansions laminar flow conditions. It shows that for the expansion cases, the aspect ratio affects more the local friction coefficients than for the contraction cases. The influence of the power index n on local friction losses is similar for both cases, abrupt contractions and abrupt expansions. At low Reynolds numbers, dilatant fluids present the lowest values of the friction coefficient, K, independent of geometry. At high Reynolds numbers, a reversal of the curves occurs, and the dilatant fluid presents larger values of K coefficient. For the cases investigated, there is also a Reynolds number in which all the curves exhibit the same value of K for any value of the power-law index. The effect of τy′ shows a different behavior between contractions and expansions. In the case of contractions, the material with the highest dimensionless yield stress has the highest K value. In the case of the expansions, the behavior is the opposite, i.e., the higher the yield stress, the lower is the values of the K coefficient. Equations for each accessory as a function of the rheological parameters of the fluid and the Reynolds number of the flow are also proposed. The data were adjusted according to two main equations: the two Ks method proposed by Hooper (1981, “The Two-K Method Predicts Head Losses in Pipe Fittings,” Chem. Eng., 81, pp. 96–100.) is used for all the contractions cases, and the equation proposed by Oliveira et al. (1997, “A General Correlation for the Local Coefficient in Newtonian Axisymmetric Sudden Expansions,” Int. J. Heat Fluid Flow, 19(6), pp. 655–660.) is used for all the expansions cases. The equations found were compared with the numerical results and showed satisfactory precision and thus can be used for engineering applications.

Sign in / Sign up

Export Citation Format

Share Document