Flow behavior of viscoelastic fluids in the inlet region of a channel

AIChE Journal ◽  
1965 ◽  
Vol 11 (6) ◽  
pp. 989-995 ◽  
Author(s):  
A. B. Metzner ◽  
J. L. White
Keyword(s):  
Flow Behavior ◽  
Viscoelastic Fluids ◽  
Inlet Region

scholarly journals Pressure Drop of Viscoelastic Fluids in the Inlet Region of a Circular Tube

1971 ◽  
Vol 14 (69) ◽  
pp. 208-216 ◽  
Author(s):  
Towa KOBAYASHI ◽  
Yukio TOMITA
Keyword(s):  
Pressure Drop ◽  
Circular Tube ◽  
Viscoelastic Fluids ◽  
Inlet Region

scholarly journals Analytical Solution of Mixed Electroosmotic/Pressure Driven Flow of Viscoelastic Fluids between a Parallel Flat Plates Micro-Channel: The Maxwell Model Using the Oldroyd and Jaumann Time Derivatives

Micromachines ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 986
Author(s):  
Laura Casas ◽  
José A. Ortega ◽  
Aldo Gómez ◽  
Juan Escandón ◽  
René O. Vargas
Keyword(s):  
Flow Behavior ◽  
Viscoelastic Fluids ◽  
Volumetric Flow Rate ◽  
Maxwell Model ◽  
Parallel Plates ◽  
Flat Plates ◽  
Practical Applications ◽  
Low Viscosity ◽  
Pressure Driven Flow ◽  
Pressure Driven

In the present work, an analytical approximate solution of mixed electroosmotic/pressure driven flow of viscoelastic fluids between a parallel plates microchannel is reported. Inserting the Oldroyd, Jaumann, or both time derivatives into the Maxwell model, important differences in the velocity profiles were found. The presence of the shear and normal stresses is only close to the wall. This model can be used as a tool to understand the flow behavior of low viscosity fluids, as most of them experiment on translation, deformation and rotation of the flow. For practical applications, the volumetric flow rate can be controlled with two parameters, namely the gradient pressure and the electrokinetic parameter, once the fluid has been rheologically characterized.

scholarly journals Electroosmotic Flow Behavior of Viscoelastic LPTT Fluid in a Microchannel

Micromachines ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 881 ◽  
Author(s):  
Dilin Chen ◽  
Jie Li ◽  
Haiwen Chen ◽  
Lai Zhang ◽  
Hongna Zhang ◽  
...  
Keyword(s):  
Newtonian Fluid ◽  
Electroosmotic Flow ◽  
Fluid Shear Stress ◽  
Viscosity Ratio ◽  
Biological Fluids ◽  
Flow Behavior ◽  
Fluid Velocity ◽  
Viscoelastic Fluids ◽  
Weissenberg Number ◽  
Fluid Medium

In many research works, the fluid medium in electroosmosis is considered to be a Newtonian fluid, while the polymer solutions and biological fluids used in biomedical fields mostly belong to the non-Newtonian category. Based on the finite volume method (FVM), the electroosmotic flow (EOF) of viscoelastic fluids in near-neutral (pH = 7.5) solution considering four ions (K+, Cl−, H+, OH−) is numerically studied, as well as the viscoelastic fluids’ flow characteristics in a microchannel described by the Linear Phan-Thien–Tanner (LPTT) constitutive model under different conditions, including the electrical double layer (EDL) thickness, the Weissenberg number (Wi), the viscosity ratio and the polymer extensibility parameters. When the EDL does not overlap, the velocity profiles for both Newtonian and viscoelastic fluids are plug-like and increase sharply near the charged wall. Compared with Newtonian fluid at Wi = 3, the viscoelastic fluid velocity increases by 5 times and 9 times, respectively, under the EDL conditions of kH = 15 and kH = 250, indicating the shear thinning behavior of LPTT fluid. Shear stress obviously depends on the viscosity ratio and different Wi number conditions. The EOF is also enhanced by the increase (decrease) in polymer extensibility parameters (viscosity ratio). When the extensibility parameters are large, the contribution to velocity is gradually weakened.

Investigation on the control of multiphase flow behavior in a continuous casting tundish during ladle change

2020 ◽  
Vol 117 (6) ◽  
pp. 619
Author(s):  
Rui Xu ◽  
Haitao Ling ◽  
Haijun Wang ◽  
Lizhong Chang ◽  
Shengtao Qiu
Keyword(s):  
Multiphase Flow ◽  
Flow Behavior ◽  
Rolled Strip ◽  
Impact Zone ◽  
Steel Cleanliness ◽  
Carry Over ◽  
Slag Carry Over ◽  
Hot Rolled ◽  
Turbulence Inhibitor ◽  
The Impact

The transient multiphase flow behavior in a single-strand tundish during ladle change was studied using physical modeling. The water and silicon oil were employed to simulate the liquid steel and slag. The effect of the turbulence inhibitor on the slag entrainment and the steel exposure during ladle change were evaluated and discussed. The effect of the slag carry-over on the water-oil-air flow was also analyzed. For the original tundish, the top oil phase in the impact zone was continuously dragged into the tundish bath and opened during ladle change, forming an emulsification phenomenon. By decreasing the liquid velocities in the upper part of the impact zone, the turbulence inhibitor decreased considerably the amount of entrained slag and the steel exposure during ladle change, thereby eliminating the emulsification phenomenon. Furthermore, the use of the TI-2 effectively lowered the effect of the slag carry-over on the steel cleanliness by controlling the movement of slag droplets. The results from industrial trials indicated that the application of the TI-2 reduced considerably the number of linear inclusions caused by ladle change in hot-rolled strip coils.

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