Modeling of Transient Two-Phase Liquid-Liquid Flow in Pipelines

2001 ◽  
Author(s):  
R. Núñez-Solís ◽  
Yuri V. Fairuzov
Keyword(s):  
Transient Flow ◽  
Fluid Pressure ◽  
Computer Code ◽  
Hilly Terrain ◽  
Two Phase ◽  
Immiscible Liquids ◽  
Fluid Transients ◽  
Phase Liquid ◽  
Oil Water ◽  
Startup Period

Abstract A study of transient oil-water flow in hilly-terrain pipelines is described in the present paper. Numerical simulation of terrain slug propagation during the line startup is performed using a novel computer code, mFLOW, for modeling transient flow of two immiscible liquids in pipelines. It is shown that a startup slug may propagate through the system without deformation of its front and tail or may dissipate. The mechanisms of slug dissipation are discussed. It is shown that the fluid pressure response is governed mainly by the process of water holdup wave propagation. It is demonstrated that the analysis of fluid transients in pipelines conveying oil-water mixtures provides useful information for the evaluation of the risk of over-pressurization during the startup period.

scholarly journals VOF Modeling and Analysis of the Segmented Flow in Y-Shaped Microchannels for Microreactor Systems

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Xian Wang ◽  
Hiroyuki Hirano ◽  
Gongnan Xie ◽  
Ding Xu
Keyword(s):  
Surface Force ◽  
Segment Length ◽  
Flow Mode ◽  
Segmented Flow ◽  
Two Phase ◽  
Immiscible Liquids ◽  
Modeling And Analysis ◽  
Transfer Rates ◽  
Phase Liquid ◽  
Simulated Flow

Microscaled devices receive great attention in microreactor systems for producing high renewable energy due to higher surface-to-volume, higher transport rates (heat or/and mass transfer rates), and other advantages over conventional-size reactors. In this paper, the two-phase liquid-liquid flow in a microchannel with various Y-shaped junctions has been studied numerically. Two kinds of immiscible liquids were injected into a microchannel from the Y-shaped junctions to generate the segment flow mode. The segment length was studied. The volume of fluid (VOF) method was used to track the liquid-liquid interface and the piecewise-liner interface construction (PLIC) technique was adopted to get a sharp interface. The interfacial tension was simulated with continuum surface force (CSF) model and the wall adhesion boundary condition was taken into consideration. The simulated flow pattern presents consistence with our experimental one. The numerical results show that a segmented flow mode appears in the main channel. Under the same inlet velocities of two liquids, the segment lengths of the two liquids are the same and depend on the inclined angles of two lateral channels. The effect of inlet velocity is studied in a typical T-shaped microchannel. It is found that the ratio between the lengths of two liquids is almost equal to the ratio between their inlet velocities.

Oil-Water Flow Visualization and Flow Regimes in a 3.7 mm Mini-Channel

2016 ◽  
Author(s):  
Kevin K. Bultongez ◽  
Melanie M. Derby
Keyword(s):  
Pressure Drop ◽  
Water Flow ◽  
Glass Tube ◽  
Flow Regimes ◽  
Two Phase ◽  
Pressure Drops ◽  
Flow Apparatus ◽  
Phase Liquid ◽  
Oil Water ◽  
Minor Losses

This study investigates adiabatic oil and water flow patterns in a 3.7-mm-inner-diameter borosilicate glass tube. A closed-loop flow apparatus was constructed and pressure drop was verified using single-phase liquid water. Minor losses were shown to be negligible, and 98% of the pressure drop occurred in the glass tube. Oil-water tests were conducted over a range of oil superficial velocities (0.27 < jo < 3.3 m/s) and water superficial velocities (0.07 < jw < 4.96 m/s). Annular, intermittent, and dispersed flow regimes were observed and shown. For nearly all cases, an annular water ring formed along the perimeter of the glass tube. Two-phase pressure drops are reported.

Numerical Simulation of Sloshing in a Tank, CFD Calculations Against Model Tests

2009 ◽  
Author(s):  
Bogdan Iwanowski ◽  
Marc Lefranc ◽  
Rik Wemmenhove
Keyword(s):  
Computer Animation ◽  
Large Scale ◽  
Stokes Equations ◽  
Fluid Pressure ◽  
Practical Interest ◽  
Physical Models ◽  
Navier Stokes ◽  
Two Phase ◽  
Navier Stokes Equations ◽  
Phase Liquid

Simulation of liquid dynamics in an LNG tank is studied numerically. The applied CFD code solves Navier-Stokes equations and uses an improved Volume of Fluid (iVOF) method to track movement of fluid’s free surface. Relative advantages of using two different fluid models, single-phase (liquid+void) and two-phase (liquid+compressible gas) are discussed, the latter model being capable of simulating bubbles and gas entrapped in liquid. Furthermore, the 1st and 2nd order upwind differencing schemes are used with both physical models leading to a total of four possible approaches to solve the problem. Numerical results are verified against experimental data from large scale (1:10) sloshing experiments of 2D section of an LNG carrier. The CFD vs. experiment comparison is shown for tank filling rates of practical interest, ranging from 10% to 95%, and includes both fluid height and fluid pressure exerted on tank walls. A visual comparison in form of computer animation frames, synchronised with camera-made movies taken during the experiments is included as well. Finally, an exhaustive computational grid convergence study is presented for lower filling rates of the tank.

Density Measurement of Three-Phase Flows Inside of Vertical Piping Using Planar Laser Induced Fluorescence PLIF

2021 ◽  
Author(s):  
Amy Brooke McCleney ◽  
Kevin Robert Supak
Keyword(s):  
High Speed ◽  
Gas Flow ◽  
Transient Flow ◽  
Two Phase ◽  
Mixture Density ◽  
Three Phase ◽  
Planar Laser ◽  
Flow Features ◽  
Oil Water ◽  
Oil Gas

Abstract Planar laser induced fluorescence (PLIF) is a measurement technique that can be used to provide a laboratory reference for validating the performance of field instrumentation that either directly measures mixture density or infers it from a combination of ancillary techniques. PLIF density measurements offer high-speed response and the ability to resolve minute flow features in transient flow patterns. Fundamentally, PLIF can also be used to verify multiphase flow models and predictive tools that are used for designing production piping. The use of PLIF to determine an instantaneous mixture density of two-phase flows has been successfully accomplished in previous fundamental laboratory studies found in literature. However, the use of this technique to determine the mixture density of three-phase flows for field-related scenarios has not been previously evaluated. To assess PLIF as a potential reference measurement system, a testing effort was undertaken to measure the instantaneous mixture density from a comingled oil-gas, water-oil, and oil-water-gas flow that was subjected to slug, churn, and bubble transient flow conditions inside of vertical piping. The objective of this work was to compare and validate the results obtained using the PLIF measurement approach against a commercially available gamma densitometer and tomography system for a variety of flowing conditions. The PLIF technique was able to resolve transient flow features and density values for both two-phase and three-phase flows through the piping. Distinct slug flow features such as the slug head, gas pocket, pocket collapse, and the tail were captured by PLIF and were observable in the raw image sequence captured by a high-speed camera. Additionally, the results for a variety of water-oil-gas flowing conditions were within 3% difference of a mixture density model that was calculated from liquid and gas flow measurements utilized in the test facility. The comparison of the PLIF results to the reference instrumentation indicates that this technique is successful at obtaining a mixture density for steady and transient oil, water, and gas comingled flows.

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