scholarly journals Hydrodynamic Modeling of Oil–Water Stratified Smooth Two-Phase Turbulent Flow in Horizontal Circular Pipes

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5201
Author(s):  
Qi Kang ◽  
Jiapeng Gu ◽  
Xueyu Qi ◽  
Ting Wu ◽  
Shengjie Wang ◽  
...  

In the petrochemical industry, multiphase flow, including oil–water two-phase stratified laminar flow, is more common and can be easily obtained through mathematical analysis. However, there is no mathematical, analytical model for the simulation of oil–water flow under turbulent flow. This paper introduces a two-dimensional (2D) numerical simulation method to investigate the pressure gradient, flow field, and oil–water interface height of a pipeline cross-section of horizontal tube in an oil–water stratified smooth flow, which has field information of a pipeline cross-section compared with a one-dimensional (1D) simulation and avoids the significant calculation required to conduct a three-dimensional (3D) simulation. Three Reynolds average N–S equation models (k−ε, k−ω, SST k−ω) are used to simulate oil–water stratified smooth flow according to the finite volume method. The pressure gradient and oil–water interface height can be computed according to the given volume flow rate using the iteration method. The predicted data of oil–water interface height and velocity profile by the model fit well with some available experiment data, except that there is a large error in pressure gradient. The SST k−ω turbulence model has higher accuracy and is more suitable for simulating oil–water two-phase stratified flow in a horizontal pipe.

2021 ◽  
Vol 1047 (1) ◽  
pp. 012021
Author(s):  
Kh Sh Ilhamov ◽  
D Z Narzullaev ◽  
Sh T Ilyasov ◽  
B A Abdurakhmanov ◽  
K K Shadmanov

2018 ◽  
Vol 74 (1) ◽  
pp. 25-41 ◽  
Author(s):  
Yuansheng He ◽  
Yingyu Ren ◽  
Yunfeng Han ◽  
Ningde Jin

AbstractThe present study is a report on the asymmetry of dispersed oil phase in vertical upward oil-water two phase flow. The multi-channel signals of the rotating electric field conductance sensor with eight electrodes are collected in a 20-mm inner diameter pipe, and typical images of low pattern are captured using a high speed camera. With the multi-channel rotating electric field conductance signals collected at pipe cross section, multi-scale time asymmetry (MSA) and an algorithm of multi-scale first-order difference scatter plot are employed to uncover the fluid dynamics of oil-water two phase flow. The results indicate that MSA can characterise the non-linear behaviours of oil-water two phase flow. Besides, the MSA analysis also beneficial for understanding the underlying inhomogeneous distribution of the flow pattern in different directions at pipe cross section.


2012 ◽  
Vol 709 ◽  
pp. 1-36 ◽  
Author(s):  
R. J. Belt ◽  
A. C. L. M. Daalmans ◽  
L. M. Portela

AbstractIn fully developed single-phase turbulent flow in straight pipes, it is known that mean motions can occur in the plane of the pipe cross-section, when the cross-section is non-circular, or when the wall roughness is non-uniform around the circumference of a circular pipe. This phenomenon is known as secondary flow of the second kind and is associated with the anisotropy in the Reynolds stress tensor in the pipe cross-section. In this work, we show, using careful laser Doppler anemometry experiments, that secondary flow of the second kind can also be promoted by a non-uniform non-axisymmetric particle-forcing, in a fully developed turbulent flow in a smooth circular pipe. In order to isolate the particle-forcing from other phenomena, and to prevent the occurrence of mean particle-forcing in the pipe cross-section, which could promote a different type of secondary flow (secondary flow of the first kind), we consider a simplified well-defined situation: a non-uniform distribution of particles, kept at fixed positions in the ‘bottom’ part of the pipe, mimicking, in a way, the particle or droplet distribution in horizontal pipe flows. Our results show that the particles modify the turbulence through ‘direct’ effects (associated with the wake of the particles) and ‘indirect’ effects (associated with the global balance of momentum and the turbulence dynamics). The resulting anisotropy in the Reynolds stress tensor is shown to promote four secondary flow cells in the pipe cross-section. We show that the secondary flow is determined by the projection of the Reynolds stress tensor onto the pipe cross-section. In particular, we show that the direction of the secondary flow is dictated by the gradients of the normal Reynolds stresses in the pipe cross-section, $\partial {\tau }_{rr} / \partial r$ and $\partial {\tau }_{\theta \theta } / \partial \theta $. Finally, a scaling law is proposed, showing that the particle-driven secondary flow scales with the root of the mean particle-forcing in the axial direction, allowing us to estimate the magnitude of the secondary flow.


2010 ◽  
Author(s):  
W. H. Liu ◽  
L. J. Guo ◽  
Liejin Guo ◽  
D. D. Joseph ◽  
Y. Matsumoto ◽  
...  

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
D. S. Santos ◽  
P. M. Faia ◽  
F. A. P. Garcia ◽  
M. G. Rasteiro

The flow of oil/water mixtures in a pipe can occur under different flow patterns. Additionally, being able to predict adequately pressure drop in such systems is of relevant importance to adequately design the conveying system. In this work, an experimental and numerical study of the fully dispersed flow regime of an oil/water mixture (liquid paraffin and water) in a horizontal pipe, with concentrations of the oil of 0.01, 0.13, and 0.22 v/v were developed. Experimentally, the values of pressure drop, flow photographs, and radial volumetric concentrations of the oil in the vertical diameter of the pipe cross section were collected. In addition, normalized conductivity values were obtained, in this case, for a cross section of the pipe where an electrical impedance tomography (EIT) ring was installed. Numerical studies were carried out in the comsolmultiphysics platform, using the Euler–Euler approach, coupled with the k–ε turbulence model. In the simulations, two equations for the calculation of the drag coefficient, Schiller–Neumann and Haider–Levenspiel, and three equations for mixture viscosity, Guth and Simba (1936), Brinkman (1952), and Pal (2000), were studied. The simulated data were validated with the experimental results of the pressure drop, good results having been obtained. The best fit occurred for the simulations that used the Schiller–Neumann equation for the calculation of the drag coefficient and the Pal (2000) equation for the mixture viscosity.


Author(s):  
Nariman Ashrafi ◽  
Mohammad Reza Ansari ◽  
Armin Chegini ◽  
Ali Sadeghi

In this article, two-phase slug regime in a duct with rectangular cross-section is investigated numerically, using the volume of fluid (VOF) method. Equations of mass, momentum and advection of volume fraction are solved accompanying k-∈ realizable turbulence equations. To ensure the creditability, numerical results have been compared with experimental results using same geometry. With occurrence of instability in the entrance of duct, Kelvin-Helmholtz condition satisfies and with increasing instability, slug phenomenon occurs. With closing the cross-section of duct, slug causes pressure gradient in it. Trapped air behind a slug transfers the momentum and increases the kinetic energy of slug. In this research the kinetic energy of a slug is investigated.


2011 ◽  
Vol 383-390 ◽  
pp. 826-829 ◽  
Author(s):  
Dao Zhen Xu ◽  
Guo Zhong Zhang ◽  
Xin Zhang

The stratified water-oil two—phase flow was modeled using VOF method in horizontal pipe and surface tension was taken into consideration using CSF model. It was found that the surface tension had great impact on the small density difference two-phase flow even in large diameter pipe, which would lead the interface curved and pressure gradient increased.


1966 ◽  
Vol 8 (1) ◽  
pp. 107-109 ◽  
Author(s):  
D. Chisholm

Relationships between the friction pressure gradient and the cross-section of the tube occupied by the liquid are developed for the flow of air-water mixtures in rough-walled horizontal tubes. The data indicate a pronounced change in the form of the relationships when the pressure gradient reaches a value of about 60 lb/ft2ft.


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