Non-Newtonian Liquid-Gas Non-Uniform Stratified Flow With Interfacial Level Gradient Through Horizontal Tubes

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Haiwang Li ◽  
Teck Neng Wong ◽  
Martin Skote ◽  
Fei Duan
Keyword(s):  
Gas Flow ◽  
Energy Equation ◽  
Liquid Velocity ◽  
Stratified Flow ◽  
Newtonian Liquid ◽  
Published Data ◽  
Axial Distribution ◽  
Two Phase ◽  
Horizontal Tubes ◽  
The Difference

This paper presents the predictions of the axial distribution of liquid level and interfacial level gradient (ILG) for nonuniform non-Newtonian liquid-gas flow in horizontal tubes. The non-Newtonian liquid is described using power-law model, while the model of Heywood and Charles for uniform non-Newtonian liquid-gas two-phase flow, which was developed based on one dimensional energy equation, is extended to describe nonuniform stratified flow by incorporating the effect of interfacial level gradient. Two different critical liquid levels are found from the energy equation and are adopted as boundary condition to calculate the interfacial level distribution upstream of the channel exit. The results from the model are compared with the published numerical and experimental data. The results show that the model can predict the interfacial level distribution and interfacial level gradient for nonuniform stratified flow. Low liquid velocity, low gas velocity and high liquid viscosity are beneficial for forming a nonuniform flow with interfacial level gradient. The difference between the analytical model and the published data is smaller than 10%.

Simulation of mechanically stirred two-phase liquid-gas flow

1986 ◽  
Vol 51 (5) ◽  
pp. 1001-1015 ◽  
Author(s):  
Ivan Fořt ◽  
Vladimír Rogalewicz ◽  
Miroslav Richter
Keyword(s):  
Spatial Distribution ◽  
Velocity Field ◽  
Gas Flow ◽  
Liquid Velocity ◽  
Model Parameters ◽  
Two Phase ◽  
Mean Velocity ◽  
Rushton Turbine ◽  
Low Viscosity ◽  
Volumetric Gas Flow Rate

The study describes simulation of the motion of bubbles in gas, dispersed by a mechanical impeller in a turbulent low-viscosity liquid flow. The model employs the Monte Carlo method and it is based both on the knowledge of the mean velocity field of mixed liquid (mean motion) and of the spatial distribution of turbulence intensity ( fluctuating motion) in the investigated system - a cylindrical tank with radial baffles at the wall and with a standard (Rushton) turbine impeller in the vessel axis. Motion of the liquid is then superimposed with that of the bubbles in a still environment (ascending motion). The computation of the simulation includes determination of the spatial distribution of the gas holds-up (volumetric concentrations) in the agitated charge as well as of the total gas hold-up system depending on the impeller size and its frequency of revolutions, on the volumetric gas flow rate and the physical properties of gas and liquid. As model parameters, both liquid velocity field and normal gas bubbles distribution characteristics are considered, assuming that the bubbles in the system do not coalesce.

scholarly journals Расчет межфазного массообмена в факеле распыла форсунки с учетом кризиса

2020 ◽  
Vol 90 (4) ◽  
pp. 560
Author(s):  
Н.Н. Симаков
Keyword(s):  
Mass Transfer ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Compressible Medium ◽  
Phase Flow ◽  
Two Phase ◽  
Turbulent Friction ◽  
Cross Section Area ◽  
Radial Profiles ◽  
The Difference

A numerical model and the results of calculation of the interfacial mass transfer in a two-phase flow formed by spraying a liquid in a gas with a nozzle are described. The basis of the proposed mathematical model is the differential equations of the nonstationary flow of a compressible medium supplemented by the equation of mass transfer from a gas to droplets. Going over to the difference analogues of the equations of continuity and phase motion, we used the well-known explicit Lax-Vendroff scheme. Herein, the axial profiles of the velocities of droplets and gas, concentrations of gas impurity in a free spray flow, as well as radial profiles of impurity concentrations in a two-phase flow through a cylindrical apparatus are calculated and presented accounting the early drag crisis of droplets, the mass-transfer crisis and the turbulent friction characteristics in gas discovered in previous experiments. Calculations show dependences of the volumetric gas flow, concentration of the gas admixture at the apparatus output, and the amount of impurity absorbed by a liquid on the height and cross-section area of the apparatus.

Numerical Research about Two-Phase Flow under Different Acceleration in SRM with Embedded Nozzle

2013 ◽  
Vol 365-366 ◽  
pp. 233-236
Author(s):  
Xiong Chen ◽  
Hai Feng Xue ◽  
Yong Luo
Keyword(s):  
Flow Field ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Particle Diameter ◽  
Phase Flow ◽  
Solid Rocket Motor ◽  
Two Phase ◽  
Axial Acceleration ◽  
The Difference ◽  
The Impact

The complex gas-solid two-phase flow in a full-sized solid rocket motor with embedded nozzle under different acceleration condition was simulated with Euler-Lagrange model. Influences of different particle diameters and acceleration conditions on particle trajectories were analyzed. Simulation results show that the difference between gas flow field and two-phase flow field is significant. The particle accumulation zone above inner wall of chamber and nozzle is mainly concentrated in two regions. The accretion of the particle diameter will cause the following property worse, and the particles can easily form a highly-concentrated aggregation flow. With the increasing of axial-acceleration, the impact point in line2 will move backward in rear head.

A Simple Model for Two-Phase Flow in Liquid-Cut Gas Wells

2013 ◽  
Vol 734-737 ◽  
pp. 1343-1349
Author(s):  
Tong Liu ◽  
Ying Chuan Li ◽  
Hai Quan Zhong
Keyword(s):  
Two Phase Flow ◽  
Liquid Velocity ◽  
Flow Patterns ◽  
Published Data ◽  
Phase Flow ◽  
Gas Wells ◽  
Two Phase ◽  
New Model ◽  
Wide Range ◽  
Phase Slippage

This paper presents a simple two-phase flow model for liquid-cut gas wells, which considers phase slippage and can be applied to various flow patterns. The model is developed from 312 measured pressure losses of gas wells in China, covering a wide range of flow patterns: annular flow, churn flow, and slug flow. Unlike most available methods, this new model introduces a derivation factor,ψ, to modify the void fraction, which not only considers the phase slippage but also unifies the slip model with the homogenous model. Parameter,ψ, is obtained from test data using the regression analyses method. It is a function of gas velocity number, liquid velocity number and liquid viscosity number. Frictional factor is estimated using the simple homogeneous modeling approach. The evaluation results using 145 published data indicate that the new model performed better than the other models.

Study of Bubble Size and Velocity in a Vibrating Bubble Column

2016 ◽  
Author(s):  
Shahrouz Mohagheghian ◽  
Brian R. Elbing
Keyword(s):  
Mass Transfer ◽  
Void Fraction ◽  
Bubble Size ◽  
Gas Flow ◽  
Bubble Column ◽  
Mass Transfer Rate ◽  
Superficial Velocity ◽  
Bubble Velocity ◽  
Published Data ◽  
Two Phase

Bubble columns are two-phase and three-phase reactors in which a gas flow drives a liquid flow and allows transport phenomena’s to take place. With a broad application from aeration of organic organisms in bio-rectors to hydrogenation of coal slurries in the Fischer-Tropsch process and production of synthetic fuel, bubble column reactors are cheap and easy to operate. In this work bubble size was studied in a bubble column and effect of injector size and gas superficial velocity was investigated. Results showed larger bubble size as gas superficial velocity was increased. It was previously shown that vibration increases the mass transfer between phases, which one active mechanism is that vibration increases the void fraction and with more gas in contact with liquid mass transfer rate increases. To check that a shaker table setup capable of generating vibration in the range of 5–15 Hz of frequency at 5 mm of amplitude using an eccentric drive mechanism was refurbished to study the bubble velocity and void fraction under vibration. The experimental setup was first verified to check if tests are repeatable and also the results are in agreement with literature. Void fraction, bubble size and velocity was measured and comparison with previously published data showed good agreement. Bubble size measurements in a stationary column showed that over the range tested bubble size increases with increasing gas superficial velocity. Bubble velocity decreases when gas superficial velocity was increased. Vibration showed a gradual reduction in bubble velocity as vibration frequency was increased.

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