Analytical and Level Set Method-Based Numerical Study for Two-Phase Stratified Flow in a Pipe

2015 ◽  
Vol 67 (11) ◽  
pp. 1253-1281 ◽  
Author(s):  
Saurish Das ◽  
Vinesh H. Gada ◽  
Atul Sharma
Keyword(s):  
Level Set Method ◽  
Level Set ◽  
Numerical Study ◽  
Stratified Flow ◽  
Two Phase

A numerical study of droplet splitting in branched T-shaped microchannel using the two-phase level-set method

2021 ◽  
Vol 13 (11) ◽  
pp. 168781402110454
Author(s):  
Mohammad Raad ◽  
Sajad Rezazadeh ◽  
Habib Jalili ◽  
Davod Abbasinezhad Fallah
Keyword(s):  
Pressure Gradient ◽  
Level Set Method ◽  
Level Set ◽  
Numerical Study ◽  
Immiscible Liquid ◽  
Length Ratio ◽  
Significant Feature ◽  
Two Phase ◽  
Droplet Splitting ◽  
Passive Technique

Droplet splitting as a significant feature of droplet-based microfluidic systems has been widely employed in biotechnology, biomedical engineering, tissue engineering, and it has been preferred over continuous flow systems. In the present paper, two-dimensional numerical simulations have been done to examine the asymmetrical droplet splitting process. The two-phase level set method (LSM) has been predicted to analyze the mechanism of droplet formation and droplet splitting in immiscible liquid/liquid two-phase flow in the branched T-junction microchannel. Governing equations on flow field have been discretized and solved using finite element-based COMSOL Multiphysics software (version 5.3a). Obtained numerical results were validated by experimental data reported in the literature which show acceptable agreement. The model was developed to simulate the mechanism of droplet splitting at the branched T-junction microchannel. This study provides a passive technique to asymmetrically split up microdroplets at the downstream T-junctions. The results show that outlet branches’ pressure gradient affects the droplet splitting. Specifically, it has been shown that the splitting ratio increases by increasing the length ratio, and equal droplet splitting can be achieved where the ratio is LL/ Lu = 1. We have used two outlet branches having the same width but different lengths to create the required pressure gradient. As the length ratio of the outlet branches increases, the diameter ratio increases as well.

scholarly journals Transition of Gas-Liquid Stratified Flow in Oil Transport Pipes

2011 ◽  
Vol 8 (2) ◽  
pp. 49 ◽  
Author(s):  
D. Lakehal ◽  
M. Labois ◽  
D. Caviezel ◽  
B. Belhouachi
Keyword(s):  
Level Set Method ◽  
Level Set ◽  
Slug Flow ◽  
Large Scale ◽  
Stratified Flow ◽  
Surface Flow ◽  
Secondary Wave ◽  
Two Phase ◽  
Pipe Length ◽  
Oil Transport

 Large-Scale Simulation results of the transition of a gas-liquid stratified flow to slug flow regime in circular 3D oil transport pipes under turbulent flow conditions expressed. Free surface flow in the pipe is treated using the Level Set method. Turbulence is approached via the LES and VLES methodologies extended to interfacial two-phase flows. It is shown that only with the Level Set method the flow transition can be accurately predicted, better than with the two-fluid phase-average model. The transition from stratified to slug flow is found to be subsequent to the merging of the secondary wave modes created by the action of gas shear (short waves) with the first wave mode (high amplitude long wave). The model is capable of predicting global flow features like the onset of slugging and slug speed. In the second test case, the model predicts different kinds of slugs, the so-called operating slugs formed upstream that fill entirely the pipe with water slugs of length scales of the order of 2-4 D, and lower size (1-1.5 D) disturbance slugs, featuring lower hold-up (0.8-0.9). The model predicts well the frequency of slugs. The simulations revealed important parameter effects on the results, such as two-dimensionality, pipe length, and water holdup. 

scholarly journals Computing three-dimensional two-phase flows with a mass-conserving level set method

2008 ◽  
Vol 11 (4-6) ◽  
pp. 221-235 ◽  
Author(s):  
S. P. van der Pijl ◽  
A. Segal ◽  
C. Vuik ◽  
P. Wesseling
Keyword(s):  
Level Set Method ◽  
Level Set ◽  
Three Dimensional ◽  
Two Phase Flows ◽  
Two Phase

Finite element implementation of an improved conservative level set method for two-phase flow

2014 ◽  
Vol 100 ◽  
pp. 138-154 ◽  
Author(s):  
Lanhao Zhao ◽  
Jia Mao ◽  
Xin Bai ◽  
Xiaoqing Liu ◽  
Tongchun Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Level Set Method ◽  
Level Set ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Finite Element Implementation ◽  
Conservative Level Set

Flux-based level-set method for two-phase flows on unstructured grids

2016 ◽  
Vol 18 (1) ◽  
pp. 31-52 ◽  
Author(s):  
Peter Frolkovič ◽  
Dmitriy Logashenko ◽  
Christian Wehner
Keyword(s):  
Level Set Method ◽  
Level Set ◽  
Unstructured Grids ◽  
Two Phase Flows ◽  
Two Phase

scholarly journals Modeling of Two-Phase Flow in Rough-Walled Fracture Using Level Set Method

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Yunfeng Dai ◽  
Zhifang Zhou ◽  
Jin Lin ◽  
Jiangbo Han
Keyword(s):  
Crude Oil ◽  
Level Set Method ◽  
Level Set ◽  
Two Phase Flow ◽  
Volume Fraction ◽  
Contact Angles ◽  
Immiscible Fluids ◽  
Water Volume ◽  
Phase Flow ◽  
Two Phase

To describe accurately the flow characteristic of fracture scale displacements of immiscible fluids, an incompressible two-phase (crude oil and water) flow model incorporating interfacial forces and nonzero contact angles is developed. The roughness of the two-dimensional synthetic rough-walled fractures is controlled with different fractal dimension parameters. Described by the Navier–Stokes equations, the moving interface between crude oil and water is tracked using level set method. The method accounts for differences in densities and viscosities of crude oil and water and includes the effect of interfacial force. The wettability of the rough fracture wall is taken into account by defining the contact angle and slip length. The curve of the invasion pressure-water volume fraction is generated by modeling two-phase flow during a sudden drainage. The volume fraction of water restricted in the rough-walled fracture is calculated by integrating the water volume and dividing by the total cavity volume of the fracture while the two-phase flow is quasistatic. The effect of invasion pressure of crude oil, roughness of fracture wall, and wettability of the wall on two-phase flow in rough-walled fracture is evaluated.

scholarly journals Patch-Recovery Filters for Curvature in Discontinuous Galerkin-Based Level-Set Methods

2016 ◽  
Vol 19 (2) ◽  
pp. 329-353 ◽  
Author(s):  
Florian Kummer ◽  
Tim Warburton
Keyword(s):  
Discontinuous Galerkin ◽  
Level Set ◽  
Numerical Study ◽  
Level Set Methods ◽  
Computational Cost ◽  
Pressure Jump ◽  
Two Phase ◽  
Two Fluids ◽  
Whole Process ◽  
Numerical Instabilities

AbstractIn two-phase flow simulations, a difficult issue is usually the treatment of surface tension effects. These cause a pressure jump that is proportional to the curvature of the interface separating the two fluids. Since the evaluation of the curvature incorporates second derivatives, it is prone to numerical instabilities. Within this work, the interface is described by a level-set method based on a discontinuous Galerkin discretization. In order to stabilize the evaluation of the curvature, a patch-recovery operation is employed. There are numerous ways in which this filtering operation can be applied in the whole process of curvature computation. Therefore, an extensive numerical study is performed to identify optimal settings for the patch-recovery operations with respect to computational cost and accuracy.

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