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

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.

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

Acta Mechanica et Automatica ◽

10.2478/ama-2019-0008 ◽

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.

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

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.791.217 ◽

2015 ◽

Vol 791 ◽

pp. 217-223 ◽

Cited By ~ 2

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.

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Pressure Drop for Oil-Gas Two-Phase Flow Through Straight Horizontal Pipe

10.2523/11069-ms ◽

2007 ◽

Author(s):

Wenhong Liu ◽

Liejin Guo ◽

Ximin Zhang ◽

Kai Lin ◽

Long Yang ◽

...

Keyword(s):

Pressure Drop ◽

Two Phase Flow ◽

Phase Flow ◽

Two Phase ◽

Horizontal Pipe ◽

Flow Through ◽

Oil Gas

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Upward Vertical Two-Phase Flow Through an Annulus—Part II: Modeling Bubble, Slug, and Annular Flow

Journal of Energy Resources Technology ◽

10.1115/1.2905916 ◽

1992 ◽

Vol 114 (1) ◽

pp. 14-30 ◽

Cited By ~ 26

Author(s):

E. F. Caetano ◽

O. Shoham ◽

J. P. Brill

Keyword(s):

Flow Pattern ◽

Annular Flow ◽

Two Phase Flow ◽

Flow Behavior ◽

Bubble Flow ◽

Phase Flow ◽

Two Phase ◽

Flow Through ◽

Physical Phenomena ◽

Good Agreement

Mechanistic models have been developed for each of the existing two-phase flow patterns in an annulus, namely bubble flow, dispersed bubble flow, slug flow, and annular flow. These models are based on two-phase flow physical phenomena and incorporate annulus characteristics such as casing and tubing diameters and degree of eccentricity. The models also apply the new predictive means for friction factor and Taylor bubble rise velocity presented in Part I. Given a set of flow conditions, the existing flow pattern in the system can be predicted. The developed models are applied next for predicting the flow behavior, including the average volumetric liquid holdup and the average total pressure gradient for the existing flow pattern. In general, good agreement was observed between the experimental data and model predictions.

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