Measurement of the Axial Pressure Distribution of Molten Polymers in Flow Through a Circular Tube

1969 ◽  
Vol 13 (4) ◽  
pp. 455-466 ◽  
Author(s):  
C. D. Han ◽  
M. Charles ◽  
W. Philippoff
Keyword(s):  
Pressure Distribution ◽  
Circular Tube ◽  
Axial Pressure ◽  
Molten Polymers ◽  
Flow Through

Gaseous dispersion in laminar flow through a circular tube

1965 ◽  
Vol 284 (1399) ◽  
pp. 540-550 ◽  
Keyword(s):  
Circular Tube ◽  
Dispersion Coefficient ◽  
Straight Tube ◽  
Laminar Regime ◽  
Thermal Conductivity Detector ◽  
Longitudinal Dispersion Coefficient ◽  
Dispersion Coefficients ◽  
Effective Dispersion ◽  
Flow Through ◽  
Gaseous Dispersion

The dispersion of a pulse of ethylene injected into nitrogen, flowing in the laminar régime through straight and curved tubes, has been investigated at pressures of 1.0 and 4.4 atm. From the study of the concentration profiles with a thermal conductivity detector (katharometer) it is found that the experimental results for gas velocities between 1.00 and 16.00 cm/s agree well with the analytical solution to this problem for a straight tube given by Sir Geoffrey Taylor and extended by Aris. In particular, at low velocities, the effective dispersion coefficients tend to the molecular diffusivities. The presence of a bend slightly reduces the effective longitudinal dispersion coefficient and the introduction of constrictions enhances it. Data are also given on a number of other gas pairs. It is concluded that measurements of dispersion provide an accurate and simple way of studying diffusion in gas mixtures.

Dispersion of matter in non-Newtonian laminar flow through a circular tube

1966 ◽  
Vol 292 (1429) ◽  
pp. 203-208 ◽  
Keyword(s):  
Laminar Flow ◽  
Newtonian Fluid ◽  
Circular Tube ◽  
Newtonian Fluids ◽  
Parallel Plane ◽  
Bingham Plastic ◽  
Ellis Model ◽  
Model Fluid ◽  
Flow Through

Taylor’s analyses of the dispersion of Newtonian fluids in laminar flow in a circular tube are extended to the flow of the Bingham plastic and Ellis model fluid. The previous results for the Newtonian fluid and power-low fluid can be deduced from the results of this work. It is indicated that Aris’s modification of Taylor’s analyses can be naturally applied to the non-Newtonian fluid. Results obtained for laminar flow between two parallel plane walls are given in the appendix.

Hot-Wire Measurements of Turbulence Correlations in a Triangular Duct

1962 ◽  
Vol 29 (4) ◽  
pp. 609-614 ◽  
Author(s):  
C. J. Cremers ◽  
E. R. G. Eckert
Keyword(s):  
Heat Transfer ◽  
Laminar Flow ◽  
Cross Section ◽  
Circular Tube ◽  
Turbulent Transport ◽  
Circular Cross Section ◽  
Hot Wire ◽  
Round Tube ◽  
Flow Through ◽  
Hot Wires

Previous studies by flow visualization have indicated that the flow through a duct of triangular cross section is in its characteristics quite different from flow through a duct with circular cross section. They revealed among others that purely laminar flow exists in the corners of the duct even though the bulk of the fluid moves in turbulent motion. Heat-transfer measurements in such a duct appear to indicate that the turbulent transport in the direction of the height of the duct is considerably smaller than expected from circular tube measurements. The present paper reports the measurements of turbulent correlations for turbulent flow through such a duct. These measurements have been made with hot wires of very small dimensions. They again reveal the existence of a laminar corner region. In the bulk of the fluid, the differences of the correlations to those in a round tube turned out to be smaller than originally suspected.

Computational study on drilling mud flow through wellbore annulus by Giesekus viscoelastic model

2020 ◽  
pp. 095440892094380
Author(s):  
Mohammad Amir Hasani ◽  
Mahmood Norouzi ◽  
Morsal Momeni Larimi ◽  
Reza Rooki
Keyword(s):  
Reynolds Number ◽  
Friction Coefficient ◽  
Pressure Drop ◽  
Elastic Property ◽  
Taylor Number ◽  
Drilling Fluids ◽  
Drilling Mud ◽  
Axial Pressure ◽  
Flow Through ◽  
Mud Flow

Cuttings transport from wellbore annulus to the surface via drilling fluids is one of the most important problems in gas and oil industries. In the present paper, the effects of viscoelastic property of drilling fluids on flow through wellbore annulus are studied numerically by use of computational fluid dynamics simulation in OpenFOAM software. This problem is simulated as the flow between two coaxial annulus cylinders and the inner cylinder is rotating through its axes. Here, the Giesekus model is used as the nonlinear constitutive equation. This model brings the nonlinear viscosity, normal stress differences, extensional viscosity and elastic property. The numerical solution is obtained using the second order finite volume method by considering PISO algorithm for pressure correction. The effect of elasticity, Reynolds number, Taylor number and mobility factor on the velocity and stress fields, pressure drop, and important coefficient of drilling mud flow is studied in detail. The results predicted that increasing elastic property of drilling mud lead to an initial sharp drop in the axial pressure gradient as well as Darcy-Weisbach friction coefficient. Increasing the Reynolds number at constant Taylor number, resulted an enhancing in the axial pressure drop of the fluid but Darcy-Weisbach [Formula: see text] friction coefficient mainly reduced.

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