Energy of Intrinsic Mode Function for Gas-Liquid Flow Pattern Identification

2012 ◽  
Vol 19 (4) ◽  
pp. 759-766 ◽  
Author(s):  
Zhiqiang Sun ◽  
Hui Gong
Keyword(s):  
Flow Pattern ◽  
Liquid Flow ◽  
Average Energy ◽  
Flow Patterns ◽  
Pattern Identification ◽  
Intrinsic Mode Function ◽  
Flow Pattern Map ◽  
Mode Function ◽  
Gas Liquid Flow ◽  
Flow Pattern Identification

Abstract Gas-liquid flows abound in a great variety of industrial processes. Correct recognition of the regimes of a gasliquid flow is one of the most formidable challenges in multiphase flow measurement. Here we put forward a novel approach to the classification of gas-liquid flow patterns. In this method a flow-pattern map is constructed based on the average energy of intrinsic mode function and the volumetric void fraction of gas-liquid mixture. The intrinsic mode function is extracted from the pressure fluctuation across a bluff body using the empirical mode decomposition technique. Experiments adopting air and water as the working fluids are conducted in the bubble, plug, slug, and annular flow patterns at ambient temperature and atmospheric pressure. Verification tests indicate that the identification rate of the flow-pattern map developed exceeds 90%. This approach is appropriate for the gas-liquid flow pattern identification in practical applications.

Flow Pattern Identification Of Gas-Liquid Flow Through Horizontal Annular Geometries

2010 ◽  
Author(s):  
Reza Ettehadi Osgouei ◽  
Mehmet Evren Ozbayoglu ◽  
Murat Ahmet Ozbayoglu ◽  
Ertan Yuksel
Keyword(s):  
Flow Pattern ◽  
Liquid Flow ◽  
Pattern Identification ◽  
Flow Through ◽  
Gas Liquid Flow ◽  
Flow Pattern Identification

Experimental Study on Flow Patterns of Decaying Swirling Gas-Liquid Flow in a Horizontal Pipe

2020 ◽  
Author(s):  
Shuai Liu ◽  
Li Liu ◽  
Jiarong Zhang ◽  
Hanyang Gu
Keyword(s):  
Flow Pattern ◽  
Liquid Flow ◽  
Separation Efficiency ◽  
Swirling Flow ◽  
Flow Patterns ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Gas Removal ◽  
Swirl Vane ◽  
Gas Liquid Flow

Abstract Swirling flow is one of the well-recognized techniques to control the working process. This special flow is widely adopted in swirl vane separators in nuclear steam generator (SG) for water droplet separation and the fission gas removal system in Thorium Molten Salt Reactor (TMSR) for gas bubble separation. Since the parameters such as separation efficiency, pressure drop and mass and heat transfer rate are strongly dependent on the flow pattern, the accurate prediction of flow patterns and their transitions is extremely important for the proper design, operation and optimization of swirling two-phase flow systems. In this paper, using air and water as working fluids, a visualization experiment is carried out to study the gas-liquid flow in a horizontal pipe containing a swirler with four helical vanes. The test pipe is 5 m in length and 30 mm in diameter. Firstly, five typical flow patterns of swirling gas-liquid flow at the outlet of the swirler are classified and defined, these being spiral chain, swirling gas column, swirling intermittent, swirling annular and swirling ribbon flow. Being affected by the different gas and liquid flow rate of non-swirling flow, it is found that the same non-swirling flow can change into different swirling flow patterns. After that, the evolution of various swirling flow patterns along the streamwise direction is analyzed considering the influence of swirl attenuation. The results indicate that the same swirling flow pattern can transform into a variety of swirling flow patterns and subsequent non-swirling flow patterns. Finally, the flow pattern maps at different positions downstream of the swirler are presented.

scholarly journals Gas–liquid Flow Pattern Recognition Based on Wavelet Packet Energy Entropy of Vortex-induced Pressure Fluctuation

2013 ◽  
Vol 13 (2) ◽  
pp. 83-88 ◽  
Author(s):  
Zhiqiang Sun ◽  
Shuai Shao ◽  
Hui Gong
Keyword(s):  
Pattern Recognition ◽  
Flow Pattern ◽  
Liquid Flow ◽  
Pressure Fluctuation ◽  
Bluff Body ◽  
Flow Direction ◽  
Wavelet Packet ◽  
Flow Patterns ◽  
Energy Entropy ◽  
Gas Liquid Flow

Here we report a novel flow-pattern map to distinguish the gas-liquid flow patterns in horizontal pipes at ambient temperature and atmospheric pressure. The map is constructed using the coordinate system of wavelet packet energy entropy versus total mass flow rate. The wavelet packet energy entropy is obtained from the coefficients of vortex-induced pressure fluctuation decomposed by the wavelet packet transform. A triangular bluff body perpendicular to the flow direction is employed to generate the pressure fluctuation. Experimental tests confirm the suitability of the wavelet packet energy entropy as an ideal indicator of the gas-liquid flow patterns. The overall identification rate of the map is 92.86%, which can satisfy most engineering applications. This method provides a simple, practical, and robust solution to the problem of gas-liquid flow pattern recognition.

Surfactant Use for Slug Flow Pattern Suppression in a Horizontal Pipe

2003 ◽  
Author(s):  
R. J. Wilkens ◽  
S. R. Glassmeyer ◽  
G. J. Rosebrock ◽  
K. M. Storage ◽  
T. M. Storage
Keyword(s):  
Flow Pattern ◽  
Liquid Flow ◽  
Pipe Flow ◽  
Slug Flow ◽  
Flow Patterns ◽  
Flow Transition ◽  
Horizontal Pipe ◽  
Surfactant Additive ◽  
Gas Liquid Flow

A set of experiments was performed to study flow pattern suppression in gas-liquid pipe flow by means of surfactant additive. Results suggest that addition of the surfactant to gas-liquid flow significantly reduces the occurrence of slug flow. In addition, previously unreported flow patterns were observed to exist between slug and dispersed bubble flows. It is concluded that new mechanisms for slug flow transition need to be considered.

scholarly journals Gas–Solid Two-Phase Flow Pattern Identification Based on Artificial Neural Network and Electrostatic Sensor Array

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3522 ◽  
Author(s):  
Fei-fei Fu ◽  
Jian Li
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Flow Pattern ◽  
Sensor Array ◽  
Flow Patterns ◽  
Pattern Identification ◽  
Phase Flow ◽  
Pneumatic Conveying ◽  
Two Phase ◽  
Flow Pattern Identification

A method for gas–solid two-phase flow pattern identification in horizontal pneumatic conveying pipelines is proposed based on an electrostatic sensor array (ESA) and artificial neural network (ANN). The ESA contains eight identical arc shaped electrodes. Numerical simulation is conducted to discuss the contributions of the electrostatic signals to the flow patterns according to the error recognition rate, and the results show that the amplitudes of the output signals from each electrode of the ESA can give important information on the particle distribution and further infer the flow patterns. In experiments, the average values and standard deviations of the eight output signals’ amplitudes are respectively extracted as the inputs of the ANN to identify four kinds of flow patterns in a pneumatic conveying pipeline, which are fully suspended flow, stratified flow, dune flow and slug flow. Results show that for any one of those two input values, the correct rates of the ANN model are all 100%.

Liquid-Liquid Flow Patterns in Microchannels

2017 ◽  
Author(s):  
Zhen Cao ◽  
Zan Wu ◽  
Mehdi Sattari Najafabadi ◽  
Bengt Sunden
Keyword(s):  
Aspect Ratio ◽  
Flow Pattern ◽  
Liquid Flow ◽  
Flow Patterns ◽  
Continuous Phase ◽  
Hydraulic Diameter ◽  
Intermittent Flow ◽  
Dimensionless Number ◽  
Dispersed Phase ◽  
Flow Pattern Map

In the present work, liquid-liquid flow patterns positioned 40 mm downstream the inlet of microchannels were experimentally investigated, including the effect of hydraulic diameter (Dh), liquid properties, aspect ratio of cross section (a) and inlet configuration. Deionized water, butanol, toluene and hexane were selected as probe fluids with water as the continuous phase. Cross-inlet microchannels of 200 μm * 200 μm (Dh = 200 μm), 400 μm * 400 μm (Dh = 400 μm), 600 μm * 600 μm (Dh = 600 μm) and 600 μm * 300 μm (Dh = 400 μm) as well as a T-inlet microchannel of 600 μm * 300 μm (Dh = 400 μm) were tested. For the tests in the microchannels of Dh = 600 μm and 400 μm, the superficial velocities of the dispersed phase and continuous phase varied between 0.3 mm/s and 12 mm/s and between 0.2 mm/s and 50 mm/s, while in the microchannel of Dh = 200 μm the superficial velocities of the dispersed phase and continuous phase ranged from 0.3 mm/s to 21 mm/s and from 0.2 mm/s to 150 mm/s. Annular flow, deformed interface flow, slug flow, intermittent flow, droplet and slug train flow and droplet flow were detected in the experiment. It shows that flow patterns depend on the hydraulic diameter, liquid properties, inlet configuration and aspect ratio significantly. Dimensionless analysis was employed to develop universal flow pattern maps regardless of the hydraulic diameter and liquid properties. It is indicated that an acceptable universal flow pattern map was derived based on the redefined dimensionless number Rei0.2 *Wei0.4, especially for the boundaries of the slug-droplet transitions, which are independent on the hydraulic diameter to some extent. The other dimensionless number Wei*Ohi worked rather effectively to develop a universal flow pattern map independent on liquid properties. The boundaries of the flow pattern transitions in different liquid-liquid flow almost overlap with each other.

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