scholarly journals Periodic Trends in Two-Phase Flow Through a Vertical Minichannel: Wavelet and Multiscale Entropy Analyses Based on Digital Camera Data

2019 ◽  
Vol 13 (1) ◽  
pp. 51-56
Author(s):  
Grzegorz Górski ◽  
Grzegorz Litak ◽  
Romuald Mosdorf ◽  
Andrzej Rysak
Keyword(s):  
Water Flow ◽  
Two Phase Flow ◽  
Digital Camera ◽  
Flow Patterns ◽  
Multiscale Entropy ◽  
Phase Flow ◽  
Periodic Patterns ◽  
Two Phase ◽  
Periodic Sequences ◽  
Flow Through

Abstract By changing the air and water flow relative rates in the two-phase (air-water) flow through a minichannel, we observe aggregation and partitioning of air bubbles and slugs of different sizes. An air bubble arrangement, which show non-periodic and periodic patterns. The spatiotemporal behaviour was recorded by a digital camera. Multiscale entropy analysis is a method of measuring the time series complexity. The main aim of the paper was testing the possibility of implementation of multiscale entropy for two-phase flow patterns classification. For better understanding, the dynamics of the two-phase flow patterns inside the minichannel histograms and wavelet methods were also used. In particular, we found a clear distinction between bubbles and slugs formations in terms of multiscale entropy. On the other hand, the intermediate region was effected by appearance of both forms in non-periodic and periodic sequences. The preliminary results were confirmed by using histograms and wavelets.

Dynamics and Noise Level Estimation in Two-Phase Flow through a Mini Channel

2016 ◽  
Vol 844 ◽  
pp. 115-121
Author(s):  
Grzegorz Górski ◽  
Grzegorz Litak ◽  
Romuald Mosdorf ◽  
Andrzej Rysak ◽  
Krzysztof Urbanowicz
Keyword(s):  
Noise Level ◽  
Two Phase Flow ◽  
Digital Camera ◽  
Phase Flow ◽  
Air Bubbles ◽  
Periodic Patterns ◽  
Two Phase ◽  
Noise Level Estimation ◽  
Flow Through ◽  
Spatio Temporal

By changing air to water flow rates of a two-phase flow through a minichannel we identified aggregation and partitioning of air bubbles and slugs of various sizes. It was found that for some flowconditions air bubbles formed periodic patterns. The identification of the spatio-temporal behaviourswas performed with a laser transitivity sensor and confirmed by a digital camera. We used the Hurstexponent to distinguish instabilities in air slugs, their breakups and aggregations. In addition, we performed noise level estimation.

Experimental Characterization of Two-Phase Flow Through Valves Applied to Liquid-Assisted Gas-Lift

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
Renato P. Coutinho ◽  
Paulo J. Waltrich ◽  
Wesley C. Williams ◽  
Parviz Mehdizadeh ◽  
Stuart Scott ◽  
...  
Keyword(s):  
Water Flow ◽  
Two Phase Flow ◽  
Numerical Study ◽  
Water Flow Rate ◽  
Phase Flow ◽  
Experimental Characterization ◽  
Two Phase ◽  
Flow Through ◽  
Gas Lift

Abstract Liquid-assisted gas-lift (LAGL) is a recently developed concept to unload wells using a gas–liquid fluid mixture. The success deployment of the LAGL technology is related to the behavior of two-phase flow through gas-lift valves. For this reason, this work presents an experimental and numerical study on two-phase flow through orifice gas-lift valves used in liquid-assisted gas-lift unloading. To the knowledge of the authors, there is no investigation in the literature on experimental characterization of two-phase flow through gas-lift valves. Experimental data are presented for methane-water flow through gas-lift valves with different orifice port sizes: 12.7 and 17.5 mm. The experiments were performed for pressures ranging from 1.00 to 9.00 MPa, gas flow rates from 0 to 4.71 m3/h, and water flow rate from 0 to 0.68 m3/min. The experimental results are compared to numerical models published in the literature for two-phase flow through restrictions and to commercial multiphase flow simulators. It is observed that some models developed for two-phase flow through restrictions could successfully characterize two-phase flow thorough gas-lift valves with errors lower than 10%. However, it is first necessary to experimentally determine the discharge coefficient (CD) for each gas-lift valve. The commercial flow simulators showed a similar performance as the models available in the literature.

Dynamics of Two-Phase Flow through a Minichannel: Fourier and Multiscale Entropy Analyses

2015 ◽  
Vol 791 ◽  
pp. 217-223 ◽  
Author(s):  
Grzegorz Górski ◽  
Grzegorz Litak ◽  
Romuald Mosdorf ◽  
Andrzej Rysak
Keyword(s):  
Light Transmission ◽  
Digital Camera ◽  
Multiscale Entropy ◽  
Air Bubbles ◽  
Periodic Patterns ◽  
Two Phase ◽  
Temporal Behaviour ◽  
Air Bubble ◽  
Flow Through ◽  
Spatio Temporal

By changing a air flow rate of the two-phase (air-water) flow through a minichannel weidentified aggregation and partitioning of air bubbles and slugs of different sizes and air bubble arrangement into periodic patterns. The identification of these spatio-temporal behaviour was doneby digital camera. Simultaneously, we provide the detailed studies of these phenomena by using thecorresponding sequences of light transmission time series recorded by a laser-phototransistor sensor.To distinguish the instabilities in air slags and their breakups and aggregations we used the Fourierand multiscale entropy analysis.

scholarly journals Two-phase flow patterns in adiabatic refrigerant flow through capillary tubes

2020 ◽  
Vol 115 ◽  
pp. 107-116 ◽  
Author(s):  
Luka Lorbek ◽  
Anja Kuhelj ◽  
Matevž Dular ◽  
Andrej Kitanovski
Keyword(s):  
Two Phase Flow ◽  
Flow Patterns ◽  
Phase Flow ◽  
Capillary Tubes ◽  
Two Phase ◽  
Flow Through

Effect of Inclination Pipe Angle on Oil-Water Two Phase Flow Patterns and Pressure Loss

2014 ◽  
Author(s):  
S. Alireza Hojati ◽  
Pedram Hanafizadeh
Keyword(s):  
Water Flow ◽  
Inclination Angle ◽  
Pressure Loss ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Phase Flow ◽  
Two Phase ◽  
Inclination Angles ◽  
Oil Water ◽  
Pipe Inclination

The flow patterns in two phase and multi-phase flows is a significant factor which influences many other parameters such as drag force, drag coefficient and pressure drop in pipe lines. One of the major streams in the gas and oil industries is oil-water two phase flow. The main flow patterns in oil-water flows are bubbly, slug, dual continuous, stratified and annular. In the present work flow patterns in two phase oil-water flow were investigated in a 0.5in diameter pipe with length of 2m. 3D simulation was used for this pipe and six types of mesh grid were used to investigate mesh independency of the simulation. The proposed numerical analyses were performed by a CFD package which is based both on volume of fluid (VOF) and Eulerian-Eulerian methods. The results showed that some flow patterns can be simulated better with VOF method and some other maybe in Eulerian-Eulerian method, so these two methods were compared with together for all flow patterns. The flow patterns may be a function of many parameters in flow. One of the important parameter which may affect flow patterns in pipe line is pipe inclination angle; therefore flow patterns in the different pipe inclination angles were investigated in two phase oil-water flow. The range of inclinations has been varied between −45 to +45 degree about the horizon. In the presented simulation oil is mixed with water via a circular hole at center of the pipe, the ratio of oil surface to water surface at entrance is 2/3 so water phase was considered as the main phase. Flow patterns were investigated for every angle of pipe and numerical results were compared with available experimental data for verification. Also the flow patterns simulated by numerical approaches were compared with available flow regime maps in the previous literatures. Finally, effect of pipe inclination angle and flow patterns on the pressure loss were investigated comprehensively.

scholarly journals Complexity of phase distribution in two-phase flow using composite multiscale entropy

2020 ◽  
Vol 135 (8) ◽  
Author(s):  
Gabriela Rafałko ◽  
Romuald Mosdorf ◽  
Grzegorz Litak ◽  
Grzegorz Górski
Keyword(s):  
Gas Phase ◽  
Two Phase Flow ◽  
Phase Distribution ◽  
Digital Camera ◽  
Flow Distribution ◽  
Multiscale Entropy ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Rates ◽  
Water Glycerol

AbstractMultiphase flow in a minichannel is a complex phenomenon which shows various patterns dynamics including slugs and bubbles depending on gas/fluid component flow rates. In this paper, air and water–glycerol mixed fluid flow has been studied. In the experiment, the volume flow rates of air and water–glycerol were changing. We studied transition of bubbles to slugs two-phase flow patterns by using multiscale entropy approach to digital camera signals and identified various patterns. The results clearly indicate that the multiscale entropy is an important complexity measure dependent on the flow distribution of the gas phase in a water–glycerol content.

scholarly journals Two-phase flow patterns in turbulent flow through a dose diffusion pipe

2005 ◽  
Vol 235 (9) ◽  
pp. 1001-1014
Author(s):  
H. Tang ◽  
L.C. Wrobel ◽  
I.E. Barton
Keyword(s):  
Turbulent Flow ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Through

Investigation on Air-Water Two-Phase Flow in Downward Minichannel

2014 ◽  
Author(s):  
Hemant B. Mehta ◽  
Jyotirmay Banerjee
Keyword(s):  
Flow Pattern ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Experimental Investigations ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Through

Experimental investigations are reported for gas-liquid two-phase flow through 2.15 mm circular minichannel. Influence of premixing of air-water two-phase flow through T-junction (TJ) and Y-junction (YJ) geometries is established. Vertical downward orientation (VDW) is selected for the experiments. Different flow patterns are observed and flow pattern maps are developed. The developed flow pattern maps are then compared with available literature. It is observed that inlet premixing play an important role for establishing the flow patterns and to develop flow pattern maps in VDW orientation.

Experimental Investigation of Air-Water Two Phase Flow Regime in Vertical Mini Pipe

2010 ◽  
Author(s):  
Pedram Hanafizadeh ◽  
Soheil Ghanbarzadeh ◽  
Arash Nouri Gheimasi ◽  
Mohammad Hassan Saidi
Keyword(s):  
Flow Pattern ◽  
Water Flow ◽  
High Speed ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Phase Flow ◽  
Two Phase ◽  
Gas Phases ◽  
Flow Pattern Map ◽  
Video Recorder

In this study the flow patterns of air-water two phase flows have been investigated experimentally in a vertical mini pipe. The flow regimes observed by 1200 fps high speed video recorder in the pipe with diameters of 2, 3 and 4 mm having the length of 27, 31 and 25cm, respectively. The comprehensive visualization of air water two phase flow in a vertical mini pipe has been performed to realize the physics of such two phase flow. Different flow patterns of air–water flow were observed simultaneously in the mini pipe at different values of air and water flow rates. Consequently the flow pattern map proposed for flow in mini-pipe in terms of superficial velocities of liquid and gas phases. The resulted flow pattern map is compared with those of other researchers in the existing literatures.

Sign in / Sign up

Export Citation Format

Share Document