Experimental Investigation of Two-Phase Flow in a Multi-Branch Reduced T-Junction With Co-Current Stratified Gas-Liquid Flow

2011 ◽  
Author(s):  
Robert Bowden ◽  
Ibrahim Hassan
Keyword(s):  
Single Phase ◽  
Phase Flow ◽  
Inlet Pipe ◽  
Critical Height ◽  
Two Phase ◽  
Gas Entrainment ◽  
Inlet Length ◽  
Phase Liquid ◽  
Gas Liquid Flow ◽  
Stratified Regime

Experiments were performed in a horizontal reduced T-junction using a branch diameter of 6.35 mm and an inlet pipe diameter of 50.8 mm. The inlet length was 1.8 m, and three branch orientations were tested at 0, 45, and 90 degrees from horizontal. Air and water, operating at 206 kPa, were used to provide a two-phase environment. Both fluids flowed co-currently within the inlet towards the branch in the smooth-stratified regime. Flow visualization was used to identify the onset of gas entrainment. The critical height at the onset of gas entrainment was quantified as a function of the single phase liquid branch Froude number for the 45, and 90 degree branches, respectively.

Co-Current Gas-Liquid Smooth-Stratified Flow in a Horizontal Reduced T-Junction Including Wavy and Slug Regime Transition Boundaries

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
Robert C. Bowden ◽  
Ibrahim G. Hassan
Keyword(s):  
Single Phase ◽  
Inlet Pipe ◽  
Critical Height ◽  
Two Phase ◽  
Gas Entrainment ◽  
Inlet Length ◽  
Phase Liquid ◽  
The Relationship ◽  
Stratified Regime ◽  
Good Agreement

Experiments were performed in a horizontal reduced T-junction using a branch diameter of 6.35 mm and an inlet pipe diameter of 50.8 mm. The inlet length was 1.8 m and three branch orientations were tested at 0, 45, and 90 degrees down from the horizontal. Water and air, operating at 206 kPa, were used to provide an adiabatic two-phase environment. Both fluids flowed co-currently within the inlet towards the branch in the smooth-stratified regime. Results demonstrate the relationship between the interface height and the inlet and branch two-phase quantities, including the inlet superficial liquid and gas velocities, and branch two-phase mass flow rate and quality. In certain instances transitions to wavy-stratified or slug regimes were observed and these limits are quantified for each branch orientation. Flow visualization was used to identify the initiation of two-phase flow in the branch, including the onsets of gas and liquid entrainment. The critical height at the onset of gas entrainment was quantified as a function of the single phase liquid branch Froude number for the 45 and 90 degree branches, respectively. The branch quality results were scaled using the critical height and showed good agreement with selected models.

Modeling Two-Phase Flow in Pipe Bends

2004 ◽  
Vol 127 (2) ◽  
pp. 204-209 ◽  
Author(s):  
Savalaxs Supa-Amornkul ◽  
Frank R. Steward ◽  
Derek H. Lister
Keyword(s):  
Pressure Drop ◽  
Single Phase ◽  
Two Phase Flow ◽  
Cfd Modeling ◽  
Phase Flow ◽  
Water Mixture ◽  
Two Phase ◽  
Candu Reactors ◽  
Phase Liquid ◽  
Visualization Experiments

In order to have a better understanding of the interaction between the two-phase steam-water coolant in the outlet feeder pipes of the primary heat transport system of some CANDU reactors and the piping material, themalhydraulic modelling is being performed with a commercial computational fluid dynamics (CFD) code—FLUENT 6.1. The modeling has attempted to describe the results of flow visualization experiments performed in a transparent feeder pipe with air-water mixtures at temperatures below 55°C. The CFD code solves two sets of transport equations—one for each phase. Both phases are first treated separately as homogeneous. Coupling is achieved through pressure and interphase exchange coefficients. A symmetric drag model is employed to describe the interaction between the phases. The geometry and flow regime of interest are a 73 deg bend in a 5.9cm diameter pipe containing water with a Reynolds number of ∼1E5-1E6. The modeling predicted single-phase pressure drop and flow accurately. For two-phase flow with an air voidage of 5–50%, the pressure drop measurements were less well predicted. Furthermore, the observation that an air-water mixture tended to flow toward the outside of the bend while a single-phase liquid layer developed at the inside of the bend was not predicted. The CFD modeling requires further development for this type of geometry with two-phase flow of high voidage.

Modeling of Interfacial Component for Two-Phase Frictional Pressure Gradient in Microchannels and Minichannels

2011 ◽  
Author(s):  
M. M. Awad ◽  
Y. S. Muzychka
Keyword(s):  
Experimental Data ◽  
Pressure Gradient ◽  
Single Phase ◽  
Simple Approach ◽  
Phase Flow ◽  
Pressure Gradients ◽  
Two Phase ◽  
Interfacial Pressure ◽  
Proposed Model ◽  
Phase Liquid

A simple approach for calculating the interfacial component of frictional pressure gradient in two-phase flow in microchannels and minichannels is presented. This approach is developed using superposition of three pressure gradients: single-phase liquid, single-phase gas, and interfacial pressure gradient. The proposed model can be transformed in two different ways. First, two-phase interfacial multiplier for liquid flowing alone (φl,i2) as a function of two-phase frictional multiplier for liquid flowing alone (φl2) and the Lockhart-Martinelli parameter, X. Second, two-phase interfacial multiplier for gas flowing alone (φg,i2) as a function of two-phase frictional multiplier for gas flowing alone (φg2) and the Lockhart-Martinelli parameter, X. This proposed model allows for the interfacial pressure gradient to be easily modeled. Comparisons of the proposed model with experimental data for microchannels and minichannels and existing correlations for both φl and φg versus X are presented.

scholarly journals Two-Phase Liquid–Liquid Flow in the Aspect of Reduction of Pumping Power of Hydrophobic Substances with High Viscosity

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2432
Author(s):  
Jerzy Hapanowicz
Keyword(s):  
Liquid Flow ◽  
Flow Resistance ◽  
Single Phase ◽  
Experimental Studies ◽  
Total Power ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Two Phase ◽  
Specific Flow ◽  
Phase Liquid

The paper reports the results of a study into a method of estimating the level of power/energy reduction needed for pumping highly viscous hydrophobic liquids. The effect of reducing the flow resistance resulting from feeding an adequate volume of water into the flow tube is considered. The polar parameters of water selected for analysis are different than oil. Experimental studies were not carried out in this regard, since the commonly accessible equation expressing the resistance of two-phase liquid–liquid flow was utilized to develop the method discussed in this study. On its basis, simulations were carried out to determine the conditions and level of reduction of the two-phase flow resistance in comparison to the single-phase flow resistance of a highly viscous oily liquid. The analysis of the results provided means for determination of such ranges of variations in the flow parameters of the two-phase liquid–liquid system, in which the total power of pumps applied to pump both liquids is smaller than the power of one pump feeding oil into the pipeline in the conditions of single-phase flow. Calculations were performed for selected constant mass flux densities of oil with various viscosities as well as for water. The proposed method can be applied in the procedure of optimization calculations for pipeline installations and their feed systems. The given example of its use was preceded by a description of the reasons and effects associated with the reduction of flow resistance in liquid–liquid systems and a detailed presentation of how to use the equation that forms the essence of the described calculation method. Attention was also paid to other phenomena accompanying two-phase liquid–liquid flows, i.e., interfacial slip, phase inversion, specific flow structures, and the viscosity of the unstable mixture of two liquids flowing in the pipe.

Pressure Drop and Heat Transfer of Magnetohydrodynamic Annular Two-Phase Flow in Rectangular Channel

1998 ◽  
Vol 120 (1) ◽  
pp. 152-159 ◽  
Author(s):  
H. Kumamaru ◽  
Y. Fujiwara
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Liquid Flow ◽  
Single Phase ◽  
Two Phase Flow ◽  
Rectangular Channel ◽  
Phase Flow ◽  
Two Phase ◽  
Phase Liquid ◽  
Single Phase Liquid Flow

An annular two-phase flow model has been proposed to predict the pressure drop and heat transfer of magnetohydrodynamic (MHD) gas-liquid metal two-phase flow in a rectangular channel for the case of high void fraction. The model for a rectangular channel, in which the applied magnetic field is perpendicular to the short side of the channel cross-section, nearly predicts Inoue et al.’s experimental data on the MHD pressure drop. For fusion reactor conditions, the model shows calculated results that the MHD pressure drop for two-phase flow can be lowered to 10 percent of that of the single-phase liquid flow and the heat transfer coefficient can be increased by a factor of two or more over that of the single-phase liquid flow.

Streaming potential from multiphase flow

Geophysics ◽  
1994 ◽  
Vol 59 (5) ◽  
pp. 707-711 ◽  
Author(s):  
Eve S. Sprunt ◽  
Tony B. Mercer ◽  
Nizar F. Djabbarah
Keyword(s):  
Multiphase Flow ◽  
Liquid Flow ◽  
Coupling Coefficient ◽  
Single Phase ◽  
Electrokinetic Potential ◽  
Streaming Potential ◽  
Two Phase ◽  
Phase Liquid ◽  
Gas Liquid Flow ◽  
Solid Liquid

In trying to understand the affect of electrokinetics on the spontaneous potential (SP) log, the focus has generally been on the solid‐brine streaming potential. Within the accuracy of the measurements, the streaming‐potential coupling coefficient is shown to be independent of the permeability of the rock. The solid‐brine streaming potential is of much smaller magnitude than the electrostatic potentials from gas‐liquid and liquid‐liquid flow. Air bubbles were found to increase the streaming potential coupling coefficient by more than two orders of magnitude over the value for single‐phase brine flow. Thus, two‐phase gas‐liquid flow is more likely to have a significant impact on the SP log than is single phase liquid flow. Two‐phase oil‐brine flow may also produce a larger electrokinetic potential than single‐phase flow. The magnitude of the electrokinetic potential caused by oil‐brine flow will depend on the composition of the oil and the brine. Trace materials can have a major impact on the electrokinetic potential of hydrocarbons. In a system with multiphase flow, the solid‐liquid interaction is probably the smallest component of the electrokinetic potential.

Asymptotic Generalizations of the Lockhart-Martinelli Method for Two Phase Flows

2009 ◽  
Author(s):  
Y. S. Muzychka ◽  
M. M. Awad
Keyword(s):  
Pressure Drop ◽  
Single Phase ◽  
Two Phase Flow ◽  
Point Of View ◽  
Phase Flow ◽  
Pressure Gradients ◽  
Two Phase ◽  
Interfacial Pressure ◽  
Phase Liquid ◽  
Flow Pressure

The Lockhart-Martinelli method for predicting two phase flow pressure drop is examined from the point of view of asymptotic modelling. Comparisons are made with the Lockhart-Martinelli method, the Chisholm method, and the Turner-Wallis method. An alternative approach for predicting two phase flow pressure drop is developed using superposition of three pressure gradients: single phase liquid, single phase gas, and interfacial pressure drop. This new approach allows for the interfacial pressure drop to be easily modelled for each type of flow regime such as: bubbly, mist, churn, plug, stratified, and annular, or based on the classical laminar-laminer, turbulent-turbulent, laminar-turbulent and turbulent-laminar flow regimes proposed by Lockhart and Martinelli.

Modelling Two-Phase Flow in Pipe Bends

2004 ◽  
Author(s):  
S. Supa-Amornkul ◽  
F. R. Steward ◽  
D. H. Lister
Keyword(s):  
Pressure Drop ◽  
Single Phase ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Water Mixture ◽  
Cfd Modelling ◽  
Two Phase ◽  
Candu Reactors ◽  
Phase Liquid ◽  
Visualization Experiments

In order to have a better understanding of the interaction between the two-phase steam-water coolant in the outlet feeder pipes of the primary heat transport system of some CANDU reactors and the piping material, themalhydraulic modelling is being performed with a commercial CFD (computational fluid dynamics) code — Fluent 6.1. The modelling has attempted to describe the results of flow visualization experiments performed in a transparent feeder pipe with air-water mixtures at temperatures below 55°C. The CFD code solves two sets of transport equations — one for each phase. Both phases are first treated separately as homogeneous. Coupling is achieved through pressure and interphase exchange coefficients. A symmetric drag model is employed to describe the interaction between the phases. The geometry and flow regime of interest are a 73° bend in a 5.9 cm-diameter pipe containing water with a Reynolds number of ∼105–106. The modelling predicted single-phase pressure drop and flow accurately. For two-phase flow with an air voidage of 5%–50%, the pressure drop measurements were less well predicted. Furthermore, the observation that an air-water mixture tended to flow toward the outside of the bend while a single-phase liquid layer developed at the inside of the bend was not predicted. The CFD modelling requires further development for this type of geometry with two-phase flow of high voidage.

Effect of Wettability on High-Velocity Coefficient in Two-Phase Gas/Liquid Flow

SPE Journal ◽  
2008 ◽  
Vol 13 (03) ◽  
pp. 298-304 ◽  
Author(s):  
Myeong H. Noh ◽  
Abbas Firoozabadi
Keyword(s):  
Liquid Flow ◽  
High Velocity ◽  
Gas Flow ◽  
Single Phase ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Gas Velocity ◽  
Two Phase ◽  
Velocity Coefficient ◽  
Gas Liquid Flow

Summary Gas-well productivity is affected by two distinct mechanisms: liquid blocking and high-velocity flow in two-phase flow. The former has been studied extensively recently, but the understanding of the latter is limited. High-velocity gas flow in single phase has been studied thoroughly by a large number of authors. Despite the fact that high-velocity coefficient in the presence of an immobile and a mobile liquid phase is much higher than that in single phase, only a handful of studies have been made on the subject. In this work, we have measured the high-velocity coefficient, ß in steady-state two-phase gas/liquid flow. The results are presented as a function of liquid relative permeability and liquid saturation. In our measurements, the wetting state is varied by the treatment with a fluorochemical compound. Then, the effect of wettability on the high-velocity coefficient in two-phase flow is investigated. Results show that when the liquid is strongly wetting, the high-velocity coefficient increases approximately 270-fold in water/gas two-phase flow. However, our data show a systematic reduction of high-velocity coefficients for the altered wetting state in two-phase flow. We present measurements of the velocity coefficients in single-phase flow and two-phase flow, for both oil/gas and water/gas flow and strong liquid-wetting and altered-wetting states. On the basis of our measurements, we conclude that the treatment of the wellbore region can result in significant improvement in well deliverability from the large reduction of high-velocity coefficients. Introduction Gas deliverability in gas-condensate reservoirs can be significantly affected by liquid blocking, either from condensate accumulation or water blocking, and high-velocity flows in the near-wellbore. Hydrocarbon blocking in gas-condensate reservoirs results in a significant loss of well productivity; water blocking from hydraulic-fracturing operation often limits the advantage of fractures. In addition to liquid blocking, the increased pressure drop, caused by inertial effects at high gas velocity in both low-permeability and hydraulically fractured reservoirs, can also result in low productivity. The focus of this work is on the high-velocity gas flow in two-phase gas/liquid flow in gas reservoirs. Darcy's law is inadequate to describe high-velocity gas flow in porous media. Through the high-velocity coefficient, ß, Darcy's law is modified, and the additional pressure drop from high-velocity flow can be expressed as the Forchheimer equation (1901). The general understanding is that the high-velocity coefficient in two-phase flow is higher than in single-phase gas flow in a dry rock. However, very few attempts have been made for conclusive experiments in determining the high-velocity coefficient in two-phase gas/liquid flow because of experimental difficulties in maintaining a constant liquid saturation for different pressure drops. Gas flow at low velocity is governed by Darcy's law, which describes a linear relationship between pressure gradient and volumetric flux. At high gas velocity, the pressure gradient required to maintain a certain flow rate through porous media is higher than that predicted by Darcy's law. The effect of inertia has to be added. The result is the Forchheimer equation expressed by[Equation 1] where µg is gas viscosity, kg is the effective gas permeability, ug is the gas volumetric flux, ß is a high-velocity coefficient, and ??g is gas density. Eq. 1 is valid both for single-phase gas flow and for two-phase gas/liquid flow provided, that the capillary effect is negligible. In 1D, one may integrate Eq. 1 to obtain [Equation 2] Here, p1 and p2 are the inlet and outlet pressure; M and jg are molecular weight and mass flux of gas, respectively; R and Z are the gas constant and the gas deviation factor, respectively; T is temperature; and L is the length. Effective gas permeability and high-velocity coefficient are determined by plotting M?p2 / 2µgZRTLjg vs. jg / µg, provided that the saturation is constant. Fig. 1 shows a schematic of determining the effective gas permeability and the high-velocity coefficient. Note that the effective permeability in Eq. 2 becomes the absolute permeability when the rock is dry (Sg = 100%, krg = 1.0). There has been much work in the literature on high gas velocity in single-phase flow in dry rocks. There has also been a fair amount of work in single-phase gas flow with immobile liquid saturation. Very little work, however, has been done in two-phase gas/liquid flow at high gas velocity. In the following, we will briefly review the literature in experimental studies and set the stage for our work in two-phase gas/liquid flow at high gas velocity.

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