scholarly journals Classification of two-phase flow patterns using multifractal analysis of pressure oscillations

2021 ◽  
Author(s):  
R. Mosdorf ◽  
G. Litak ◽  
G. Górski ◽  
J. Augustyniak ◽  
I. Zaborowska
Keyword(s):  
Multifractal Analysis ◽  
Two Phase Flow ◽  
Complexity Analysis ◽  
Spectral Width ◽  
Flow Patterns ◽  
Qualitative Assessment ◽  
Phase Flow ◽  
Pressure Oscillations ◽  
Two Phase

AbstractThe two-phase flow patterns (air–water) in horizontal square minichannel (3 × 3 mm) has been analysed. The multifractal analysis of pressure drop fluctuations was used for qualitative assessment of two-phase flow patterns. The results of the complexity analysis using the multifractal spectral width (Δh) are presented. The proposed method allows us to identify the following two-phase flow patterns: micro-bubbles flow, micro- and minibubbles flow, micro- and mini-bubbles with confined bubbles flow, slug flow, stratified flow. The obtained results confirm that this type of analysis can be considered as an alternative way of identification of two-phase flow patterns in the minichannel. The work also focuses on the discussion of the occurrence and identification of bubbles churns in slugs and churns.

CLASSIFICATION OF FLOW PATTERNS IN TWO PHASE FLOW BY NEURAL NETWORK

1991 ◽  
pp. 1617-1620 ◽  
Author(s):  
Norio BABA ◽  
Yoshiyuki YAMASHITA ◽  
Yasuhiro SHIRAISHI
Keyword(s):  
Neural Network ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Phase Flow ◽  
Two Phase

Application of convolutional neural networks for the classification of two-phase flow patterns

2021 ◽  
Author(s):  
I. Urbina-Salas ◽  
E. E. Vazquez-Ramirez ◽  
E. Garcia-Sanchez ◽  
E. D. Martinez-Rodriguez ◽  
L. Garcia-Garcia ◽  
...  
Keyword(s):  
Neural Networks ◽  
Convolutional Neural Networks ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Phase Flow ◽  
Two Phase

Classification of natural circulation two-phase flow patterns using fuzzy inference on image analysis

2012 ◽  
Vol 250 ◽  
pp. 592-599 ◽  
Author(s):  
R.N. de Mesquita ◽  
P.H.F. Masotti ◽  
R.M.L. Penha ◽  
D.A. Andrade ◽  
G. Sabundjian ◽  
...  
Keyword(s):  
Image Analysis ◽  
Two Phase Flow ◽  
Fuzzy Inference ◽  
Natural Circulation ◽  
Flow Patterns ◽  
Phase Flow ◽  
Two Phase

CLASSIFICATION OF FLOW PATTERNS IN TWO-PHASE FLOW BY FUZZY SIMULATOR

1987 ◽  
Vol 59 (1-6) ◽  
pp. 325-331 ◽  
Author(s):  
YOSHIYUKI YAMASHITA ◽  
SHIGERU MATSUMOTO ◽  
MUTSUMI SUZUKI
Keyword(s):  
Two Phase Flow ◽  
Flow Patterns ◽  
Phase Flow ◽  
Two Phase

scholarly journals Classification of Two-Phase Flow Patterns by Ultrasonic Sensing

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
Devesh K. Jha ◽  
Asok Ray ◽  
Kushal Mukherjee ◽  
Subhadeep Chakraborty
Keyword(s):  
Pattern Classification ◽  
Nuclear Power ◽  
Power Plants ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Industrial Applications ◽  
Phase Flow ◽  
Two Phase ◽  
Ultrasonic Sensing

This paper presents a methodology for classification of two-phase flow patterns in fluid systems, which takes the measurements of an in situ ultrasonic sensor as inputs. In contrast to the common practice of having an array of ultrasonic detectors, the underlying algorithm requires only a single sensor hardware in combination with an integrated software of signal conditioning, feature extraction, and pattern classification. The proposed method is noninvasive and can be implemented in a variety of industrial applications (e.g., petrochemical processes and nuclear power plants). This concept of flow pattern classification is experimentally validated on a laboratory test apparatus.

scholarly journals Two-Phase Flow Mass Transfer Analysis of Airlift Pump for Aquaculture Applications

Fluids ◽  
2021 ◽  
Vol 6 (6) ◽  
pp. 226
Author(s):  
Rashal Abed ◽  
Mohamed M. Hussein ◽  
Wael H. Ahmed ◽  
Sherif Abdou
Keyword(s):  
Mass Transfer ◽  
Oxygen Transfer ◽  
Transfer Rate ◽  
Two Phase Flow ◽  
Oxygen Transfer Rate ◽  
Flow Patterns ◽  
Oxygen Mass Transfer ◽  
Phase Flow ◽  
Two Phase ◽  
Airlift Pump

Airlift pumps can be used in the aquaculture industry to provide aeration while concurrently moving water utilizing the dynamics of two-phase flow in the pump riser. The oxygen mass transfer that occurs from the injected compressed air to the water in the aquaculture systems can be experimentally investigated to determine the pump aeration capabilities. The objective of this study is to evaluate the effects of various airflow rates as well as the injection methods on the oxygen transfer rate within a dual injector airlift pump system. Experiments were conducted using an airlift pump connected to a vertical pump riser within a recirculating system. Both two-phase flow patterns and the void fraction measurements were used to evaluate the dissolved oxygen mass transfer mechanism through the airlift pump. A dissolved oxygen (DO) sensor was used to determine the DO levels within the airlift pumping system at different operating conditions required by the pump. Flow visualization imaging and particle image velocimetry (PIV) measurements were performed in order to better understand the effects of the two-phase flow patterns on the aeration performance. It was found that the radial injection method reached the saturation point faster at lower airflow rates, whereas the axial method performed better as the airflow rates were increased. The standard oxygen transfer rate (SOTR) and standard aeration efficiency (SAE) were calculated and were found to strongly depend on the injection method as well as the two-phase flow patterns in the pump riser.

Two-Phase Flow and Heat Transfer in Rectangular Micro-Channels

2003 ◽  
Author(s):  
Weilin Qu ◽  
Seok-Mann Yoon ◽  
Issam Mudawar
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Flow Pattern ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Heat Sinks ◽  
Phase Flow ◽  
Micro Channel ◽  
Two Phase ◽  
Micro Channels

Knowledge of flow pattern and flow pattern transitions is essential to the development of reliable predictive tools for pressure drop and heat transfer in two-phase micro-channel heat sinks. In the present study, experiments were conducted with adiabatic nitrogen-water two-phase flow in a rectangular micro-channel having a 0.406 × 2.032 mm cross-section. Superficial velocities of nitrogen and water ranged from 0.08 to 81.92 m/s and 0.04 to 10.24 m/s, respectively. Flow patterns were first identified using high-speed video imaging, and still photos were then taken for representative patterns. Results reveal that the dominant flow patterns are slug and annular, with bubbly flow occurring only occasionally; stratified and churn flow were never observed. A flow pattern map was constructed and compared with previous maps and predictions of flow pattern transition models. Annual flow is identified as the dominant flow pattern for conditions relevant to two-phase micro-channel heat sinks, and forms the basis for development of a theoretical model for both pressure drop and heat transfer in micro-channels. Features unique to two-phase micro-channel flow, such as laminar liquid and gas flows, smooth liquid-gas interface, and strong entrainment and deposition effects are incorporated into the model. The model shows good agreement with experimental data for water-cooled heat sinks.

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