Two-Phase Flow in an Annular Channel With an Obstacle

2012 ◽  
Author(s):  
O. N. Kashinsky ◽  
P. D. Lobanov ◽  
A. S. Kurdyumov ◽  
N. A. Pribaturin
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Void Fraction ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Annular Channel ◽  
Electrochemical Technique ◽  
Phase Flow ◽  
Two Phase ◽  
Wall Shear

Experimental study of gas-liquid two-phase flow in an annular channel is performed. The channel consisted of two coaxial tubes with the diameters of 42 and 20 mm. An obstacle covering a quarter of the channel section was placed in the channel to produce a strong three-dimensional disturbance of the flow. Gas-liquid flow was produced by injecting air bubbles at the channel entrance through a special mixer. Measurements of local wall shear stress are performed using an electrochemical technique. Measurements of time-averaged and fluctuational wall shear stress are performed at various points relative to the obstacle, this allowed to study the field of the hydrodynamic parameters of the flow. Local void fraction is measured using a conductivity probe which traversed across the channel. The distribution of local void fraction in the region downstream the obstacle is obtained. Increased values of local void fraction in the region close to the obstacle are detected. The experimental data obtained can be used for validation of existing and developing computer codes accounting for a 3-D structure of two-phase flows.

Development of a Transient Mechanistic Two-Phase Flow Model for Wellbores

SPE Journal ◽  
2012 ◽  
Vol 17 (03) ◽  
pp. 942-955 ◽  
Author(s):  
Mahdy Shirdel ◽  
Kamy Sepehrnoori
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Two Phase Flow ◽  
Fluid Model ◽  
Flow Regimes ◽  
Phase Flow ◽  
Two Phase ◽  
Wall Shear ◽  
Two Fluid Model ◽  
Two Fluid

Summary A great deal of research has been focused on transient two-phase flow in wellbores. However, there is lack of a comprehensive two-fluid model in the literature. In this paper, we present an implementation of a pseudo-compositional, thermal, fully implicit, transient two-fluid model for two-phase flow in wellbores. In this model, we solve gas/liquid mass balance, gas/liquid momentum balance, and two-phase energy balance equations to obtain five primary variables: liquid velocity, gas velocity, pressure, holdup, and temperature. This simulator can be used as a stand-alone code or can be used in conjunction with a reservoir simulator to mimic wellbore/reservoir dynamic interactions. In our model, we consider stratified, bubbly, intermittent, and annular flow regimes using appropriate closure relations for interphase and wall-shear stress terms in the momentum equations. In our simulation, we found that the interphase and wall-shear stress terms for different flow regimes can significantly affect the model's results. In addition, the interphase momentum transfer terms mainly influence the holdup value. The outcome of this research leads to a more accurate simulation of multiphase flow in the wellbore and pipes, which can be applied to the surface facility design, well-performance optimization, and wellbore damage estimation.

Development of a wall shear stress integral measurement and analysis system for two-phase flow boundary layers

2006 ◽  
Vol 77 (10) ◽  
pp. 105103 ◽  
Author(s):  
Elvis E. Dominguez-Ontiveros ◽  
Carlos E. Estrada-Perez ◽  
Javier Ortiz-Villafuerte ◽  
Yassin A. Hassan
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Boundary Layers ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Boundary ◽  
Measurement And Analysis ◽  
Wall Shear ◽  
Analysis System

Wall shear stress measurements in vertical air-water annular two-phase flow

1989 ◽  
Vol 15 (3) ◽  
pp. 307-325 ◽  
Author(s):  
A.H. Govan ◽  
G.F. Hewitt ◽  
D.G. Owen ◽  
G. Burnett
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Stress Measurements ◽  
Wall Shear

Numerical Study of Flow Dynamics in Human Eye Vitreous Chamber After Vitrectomy and Gas Tamponade

2015 ◽  
Author(s):  
Ali Yousefi ◽  
Omid Abouali ◽  
Ebrahim Ghoshtasbi Rad ◽  
Goodarz Ahmadi
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Two Phase Flow ◽  
Numerical Study ◽  
Maximum Shear Stress ◽  
Phase Flow ◽  
Two Phase ◽  
Human Eye ◽  
Gas Tamponade ◽  
Wall Shear

The purpose of this study is to evaluate the flow pattern and the fluid shear stress acting on the retinal wall in a human eye vitreous chamber after Vitrectomy and gas tamponade including the effect of saccadic eye movements. The correlation between the maximum shear stress induced on the retinal wall and the gas fill fraction (GF) and saccade amplitudes was investigated. In modeling the geometry of vitreous chamber cavity, the indentation of the lens was taken into account. The two-phase flow at the recovery phase of the operation was modeled numerically. Unsteady three-dimensional forms of continuity and Navier-Stokes equations were solved. Volume-of-fluid method was used to solve the two-phase flow in the eye. Saccadic motion of the eye was modeled using the dynamic mesh technique. The numerical model was validated by comparing the results with the available analytical solutions and experimental data for a spherical model. Then, numerical simulation was performed based on the deformed sphere configuration, representing a more realistic model of vitreous chamber cavity. The simulation results were compared with the available numerical studies for the spherical geometry. Then the wall shear stress on the retina was computed and compared for various gas fractions. The potential effect of wall shear stress on the retinal detachment and the need for post-operation posturing in all studied cases were discussed.

scholarly journals Effects of Rotation Speeds on Electrical Submersible Pump Performance under Two-Phase Flow

2021 ◽  
Vol 16 ◽  
pp. 158-167
Author(s):  
Abdulqader Hasan ◽  
Mohamed S. Gadala ◽  
Salman Shahid ◽  
Mohd Shiraz Aris ◽  
Sharul Sham Dol ◽  
...  
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Flow Rate ◽  
Single Phase ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Submersible Pump ◽  
Two Phase ◽  
Electrical Submersible Pump ◽  
Wall Shear

The effects of the wall shear stress on an Electrical Submersible Pump (ESP) was investigated in this paper. A CFD model in ANSYS Fluent was proposed to simulate actual single-phase and two-phase flow. The bottom hole pressure was minimized by utilizing the artificial lift methods. The flowing fluids in pumps and pipes causes shear stress on surface interacting. In multiphase flow application pump damages on head degradation as well as shear stress affects. The K-ω turbulence model and the multiphase Mixture approach with the sliding technique used to solve the Navier-Stokes equation. To study the effects of gas-liquid (air-water) flow on the ESP and the pump handle ability, the rotation speeds were varied while the other parameters were kept constant. The rotation speeds simulated were at 500, 900, 1500, 2000 and 2500 rpm meanwhile the water flow rate and gas flow rate were kept constant with 20 L/min and 1% fraction, respectively. The results obtained show that as the rotation speeds were increased, the less concentration of the bubbles were observed, moreover the wall shear stress (WSS) increases. Although, the wall shear stress in both single-phase and two-phase flow were tend to increase as the blades length increased, however for the single-phase flow the WSS was found higher in all the simulated rotational speeds.

Heat Transfer and Turbulent Structure in an Annular Channel With an Obstacle

2014 ◽  
Author(s):  
O. N. Kashinsky ◽  
P. D. Lobanov ◽  
A. S. Kurdyumov ◽  
N. A. Pribaturin
Keyword(s):  
Heat Transfer ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Turbulent Flows ◽  
Three Dimensional ◽  
Annular Channel ◽  
Electrochemical Technique ◽  
Flow Measurements ◽  
Flow And Heat Transfer ◽  
Wall Shear

Experimental study of liquid flow and heat transfer in an annular channel is performed. The channel consisted of two coaxial tubes with the diameters of 42.2 and 20 mm. An obstacle covering a quarter of the channel section was placed in the channel to produce a strong three-dimensional disturbance of the flow. Measurements of local wall shear stress are performed using an electrochemical technique. Measurements of heat transfer, time-averaged and fluctuational wall shear stress are performed at various points relative to the obstacle, this allowed to study the field of the hydrodynamic parameters of the flow. The experimental data obtained can be used for validation of existing and developing computer codes accounting for a 3-D structure of turbulent flows.

M810 Study of wall-shear stress during bubble passage in gas-liquid two-phase flow in a horizontal duct

2016 ◽  
Vol 2016.91 (0) ◽  
pp. 344
Author(s):  
NAOKI SHIRO ◽  
HIDEKI MURAKAWA ◽  
KATUMI SUGIMOTO ◽  
NOBUYUKI TAKENAKA
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Wall Shear

Measurement of Three-Dimensional Time-Averaged Void Fraction Distribution in Rod Bundle in Air-Water System by X-Ray CT Technique

2013 ◽  
Author(s):  
Kenichi Katono ◽  
Jun Nukaga ◽  
Takuji Nagayoshi ◽  
Kenichi Yasuda
Keyword(s):  
Fuel Assembly ◽  
Void Fraction ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Ct Images ◽  
Phase Flow ◽  
Two Phase ◽  
X Ray ◽  
Void Fraction Distribution ◽  
Fraction Distribution

We have been developing a void fraction distribution measurement technique using the three-dimensional (3D) time-averaged X-ray CT (computed tomography) system to understand two-phase flow behavior inside a fuel assembly for BWR (boiling water reactor) thermal hydraulic conditions of 7.2 MPa and 288 °C. Unlike CT images of a normal standstill object, we can obtain 3D CT images that are reconstructed from time-averaged X-ray projection data of the intermittent two-phase flow. We measured the 3D void fraction distribution in a vertical square (5 × 5) rod array that simulated a BWR fuel assembly in the air-water test. From the 3D time-averaged CT images, we confirmed that the void fraction at the center part of the channel box was higher than that near the channel box wall, and the local void fraction at the central region of a subchannel was higher than that at the gap region of the subchannel. A comparison of the volume-averaged void fractions evaluated by the developed X-ray CT system with those evaluated by a differential pressure transducer in a void fraction range from 0.05 to 0.40 showed satisfactory agreement within a difference of 0.03.

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