Effect of Fluid Properties on Two-Phase Froth Characteristics

1999 ◽  
Vol 38 (10) ◽  
pp. 4110-4112 ◽  
Author(s):  
Dingwu Feng ◽  
Chris Aldrich
Keyword(s):  
Two Phase ◽  
Fluid Properties

Modeling Gas-Liquid Head Performance of Electrical Submersible Pumps

2004 ◽  
Author(s):  
Datong Sun ◽  
Mauricio Prado
Keyword(s):  
Petroleum Industry ◽  
Nuclear Industry ◽  
Two Phase ◽  
Liquid Model ◽  
Electrical Submersible Pumps ◽  
Pump Head ◽  
Fluid Properties ◽  
Interfacial Characteristic ◽  
Model Equations ◽  
Shock Loss

This study presents a new gas-liquid model to predict Electrical Submersible Pumps (ESP) head performance. The newly derived approach based on gas-liquid momentum equations along pump channels has improved the Sachdeva model [1, 2] in the petroleum industry and generalized the Minemura model [3] in the nuclear industry. The new two-phase model includes novel approaches for wall frictional losses for each phase using a gas-liquid stratified assumption and existing correlations, a new shock loss model incorporating rotational speeds, a new correlation for drag coefficient and interfacial characteristic length effects by fitting the model results with experimental data, and an algorithm to solve the model equations. The model can predict pressure and void fraction distributions along impellers and diffusers in addition to the pump head performance curve under different fluid properties, pump intake conditions, and rotational speeds.

scholarly journals Simulation of Surfactant Oil Recovery Processes and the Role of Phase Behaviour Parameters

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 983 ◽  
Author(s):  
Pablo Druetta ◽  
Francesco Picchioni
Keyword(s):  
Oil Recovery ◽  
Phase Behaviour ◽  
Residual Oil ◽  
Two Phase ◽  
Oil Saturation ◽  
Recovery Processes ◽  
Fluid Properties ◽  
Injection Water ◽  
Finitedifference Method

Chemical Enhanced Oil Recovery (cEOR) processes comprise a number of techniques whichmodify the rock/fluid properties in order to mobilize the remaining oil. Among these, surfactantflooding is one of the most used and well-known processes; it is mainly used to decrease the interfacialenergy between the phases and thus lowering the residual oil saturation. A novel two-dimensionalflooding simulator is presented for a four-component (water, petroleum, surfactant, salt), two-phase(aqueous, oleous) model in porous media. The system is then solved using a second-order finitedifference method with the IMPEC (IMplicit Pressure and Explicit Concentration) scheme. The oilrecovery efficiency evidenced a strong dependency on the chemical component properties and itsphase behaviour. In order to accurately model the latter, the simulator uses and improves a simplifiedternary diagram, introducing the dependence of the partition coefficient on the salt concentration.Results showed that the surfactant partitioning between the phases is the most important parameterduring the EOR process. Moreover, the presence of salt affects this partitioning coefficient, modifyingconsiderably the sweeping efficiency. Therefore, the control of the salinity in the injection water isdeemed fundamental for the success of EOR operations with surfactants.

On the Application of the Method of Landau and Lifshitz to Sonic Velocities in Homogeneous Two-Phase Mixtures

1996 ◽  
Vol 118 (1) ◽  
pp. 186-188 ◽  
Author(s):  
Joseph C. Leung
Keyword(s):  
Thermal Equilibrium ◽  
Mass Fraction ◽  
Sonic Velocity ◽  
Simple Correlation ◽  
Velocity Correlation ◽  
Two Phase ◽  
Fluid Properties ◽  
Vapor Mass

A theoretical sonic velocity correlation for homogeneous two-phase mixtures under thermal equilibrium is proposed. By application of the method of Landau and Lifshitz, a dimensionless correlating parameter ω is found whereby different fluid properties and vapor mass fraction (quality) can be adequately accounted for by the simple correlation.

Damping of Heat Exchanger Tubes in Two-Phase Flow: Review and Design Guidelines

2004 ◽  
Vol 126 (4) ◽  
pp. 523-533 ◽  
Author(s):  
M. J. Pettigrew ◽  
C. E. Taylor
Keyword(s):  
Heat Exchanger ◽  
Two Phase Flow ◽  
Cross Flow ◽  
Design Guidelines ◽  
Phase Flow ◽  
Flow Induced Vibration ◽  
Two Phase ◽  
Design Guideline ◽  
Fluid Properties ◽  
Semi Empirical

Two-phase flow exists in many shell-and-tube heat exchangers such as condensers, evaporators, and nuclear steam generators. Some knowledge on tube damping mechanisms is required to avoid flow-induced vibration problems. This paper outlines the development of a semi-empirical model to formulate damping of heat exchanger tube bundles in two-phase cross flow. The formulation is based on information available in the literature and on the results of recently completed experiments. The compilation of a database and the formulation of a design guideline are outlined in this paper. The effects of several parameters such as flow velocity, void fraction, confinement, flow regime and fluid properties are discussed. These parameters are taken into consideration in the formulation of a practical design guideline.

Numerical Modeling and Validation of Supersonic Two-Phase Flow of CO2 in Converging-Diverging Nozzles

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Miad Yazdani ◽  
Abbas A. Alahyari ◽  
Thomas D. Radcliff
Keyword(s):  
Phase Change ◽  
Velocity Model ◽  
Attractive Alternative ◽  
Sonic Velocity ◽  
Shock Train ◽  
Alternative Refrigerants ◽  
Two Phase ◽  
Expansion Waves ◽  
Fluid Properties ◽  
Layer Flow

Carbon dioxide is an attractive alternative to conventional refrigerants due to its low direct global warming effects. Unfortunately, CO2 and many alternative refrigerants have lower thermodynamic performance resulting in larger indirect emissions. The effective use of ejectors to recover part of the lost expansion work, which occurs in throttling devices, can close this performance gap and enable the use of CO2. In an ejector, the pressure of the motive fluid is converted into momentum through a choked converging-diverging nozzle, which then entrains and raises the energy of a lower-momentum suction flow. In a two-phase ejector, the motive nozzle flow is complicated by the nonequilibrium phase change affecting local sonic velocity and leading to various types of shockwaves, pseudo shocks, and expansion waves inside or outside the exit of the nozzle. Since the characteristics of the jet leaving the motive nozzle greatly affect the performance of the ejector, this paper focuses on the details of flow development and shockwave interaction within and just outside the nozzle. The analysis is based on a high-fidelity model that incorporates real-fluid properties of CO2, local mass and energy transfer between phases, and a two-phase sonic velocity model in the presence of finite-rate phase change. The model has been validated against the literature data for two-phase supersonic nozzles and overall ejector performance data. The results show that due to nonequilibrium effects and delayed phase change, the flow can choke well downstream of the minimum-area throat. In addition, Mach number profiles show that, although phase change is at a maximum near the boundaries, the flow first becomes supersonic in the interior of the flow where sound speed is lowest. Shock waves occurring within the nozzle can interact with the boundary layer flow and result in a ‘shock train’ and a sequence of subsonic and supersonic flow previously observed in single-phase nozzles. In cases with lower nozzle back pressure, the flow continues to accelerate through the nozzle and the exit pressure adjusts in a series of supersonic expansion waves.

A Simple Two-Phase Frictional Multiplier Calculation Method

2004 ◽  
Author(s):  
M. M. Awad ◽  
Y. S. Muzychka
Keyword(s):  
Mass Flux ◽  
Homogeneous Model ◽  
Mass Effect ◽  
The Other ◽  
High Mass ◽  
Two Phase ◽  
Simple Method ◽  
Consistent Manner ◽  
Fluid Properties ◽  
Fanning Friction Factor

In this paper, a simple method for calculating two-phase frictional multiplier for total flow assumed liquid in the pipe φlo2 is presented. The homogeneous model is used to calculate the fluid properties (density and viscosity). The Churchill model is used to define the Fanning friction factor to take into account the effect of the mass flux on φlo2. Effect of stream pressure on φlo2 is also investigated. It is found that φlo2 decreases with increasing the stream pressure at a given mass quality and reaches 1 at the critical pressure. On the other hand, it is found that φlo2 increases with increasing the mass flux at a given mass quality. Comparison with other existing correlations for calculating φlo2 such as the Wallis correlation based on the homogeneous model without mass effect on φlo2, the Martinelli-Nelson correlation, the Chisholm correlation, and the Friedel correlation is presented. When the mass flux value becomes low, the effect of mass flux on φlo2 becomes small and present correlation approaches the Wallis correlation. Both the present correlation and the Wallis correlation approach the maximum two-phase frictional multiplier in a smooth consistent manner while the other correlations show a peaking effect at high mass qualities. The Friedel correlation shows better agreement with the present correlation than both the Martinelli-Nelson correlation and the Chisholm correlation. Comparison with results from other experimental test facilities for calculating φlo2 is also presented. Comparison with other experimental data shows better agreement with the present correlation than the Martinelli-Nelson correlation.

Thermo-Fluid Dynamic Analysis on the Compression Process of Liquid-Gas Two-Phase

2016 ◽  
Author(s):  
Abhay Mohan ◽  
Palani Kumar Chidambaram ◽  
Abhilash Suryan ◽  
Heuy Dong Kim
Keyword(s):  
Fluid Dynamic ◽  
Compression Process ◽  
Two Phase ◽  
Fluid Mixture ◽  
Turbine Engine ◽  
High Enthalpy ◽  
Fluid Properties ◽  
Cylinder Piston ◽  
Compressor Work ◽  
Wet Compression

In a typical compressor - turbine cycle, the majority of the output power from the turbine is consumed for the operation of the compressor. In order to obtain higher output from turbines, certain techniques are employed to reduce compressor work. It is known that the compressor work increases continually with the increase in temperature of the operating fluid. One of the techniques to achieve reduction of temperature of the fluid is through the inter-cooling between the compressor stages. But this may lead to the decrease in the overall efficiency of the cycle. Another concept is to utilize the high enthalpy of vaporization of water. One of these techniques is known as wet compression. Here water droplets are introduced into the compressor and the fluid mixture is compressed. The droplets absorb the heat from the surroundings and evaporate, and thus reduces the temperature of the operating fluid. This in turn decreases the compression work. Also in order to maintain the O/F ratio of gas turbine, the mass flow rate of the fuel will also increase. All the above mentioned factors thus increase the net power output of the turbine engine. For the current study, a cylinder-piston system containing air involving fine droplets of water is modeled as a simple representation of the wet compression process. The compression process is achieved by the movement of the piston. Thermodynamic properties such as pressure and temperature are investigated in detail for different parameters such as rates of compression, droplet mass and sizes. Analytical equations are derived and validated using the classical D-square law. These equations are used in order to track the change in fluid properties during the compression process and its deviation from dry air compression. The results thus obtained are discussed in terms of the rates of compression, absolute and relative humidities. Corresponding thermodynamic curves are generated which are seen to deviate significantly from the dry isentropic curves. It is observed that smaller diameter droplets, slower speeds of compression and higher amount of overspray percentages lead to lower compressor work.

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