Characterization of oil/water two-phase flow patterns based on symbolic time series analysis

2004 ◽  
Author(s):  
Jin Ningde ◽  
Li Weibo ◽  
Zhao Xin ◽  
Liu Xingbin
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Phase Flow ◽  
Two Phase ◽  
Series Analysis ◽  
Oil Water ◽  
Symbolic Time Series Analysis

Non-Linear Time Series Analysis of the Infuence of Rolling Motion on Natural Circulation System

2010 ◽  
Author(s):  
Wenchao Zhang ◽  
Sichao Tan ◽  
Puzhen Gao
Keyword(s):  
Experimental Data ◽  
Time Series ◽  
Time Series Analysis ◽  
Two Phase Flow ◽  
Flow Instability ◽  
Natural Circulation ◽  
Rolling Motion ◽  
Phase Flow ◽  
Two Phase ◽  
Series Analysis

Two-phase natural circulation flow instability under rolling motion condition was studied experimentally and theoretically. Experimental data were analyzed with nonlinear time series analysis methods. The embedding dimension, correlation dimension and K2 entropy were determined based on phase space reconstruction theory and G-P method. The maximal Lyapunov exponent was calculated according to the methods of small data sets. The nonlinear features of the two phase flow instability under rolling motion were analyzed with the results of geometric invariants coupling with the experimental data. The results indicated that rolling motion strengthened the nonlinear characteristics of two phase flow instability. Some typical nonlinear phenomena such as period-doubling bifurcations and chaotic oscillations were found in different cases.

scholarly journals Detection of Two-Phase Flow Patterns in a Vertical Minichannel Using the Recurrence Quantification Analysis

2015 ◽  
Vol 9 (2) ◽  
pp. 99-104
Author(s):  
Romuald Mosdorf ◽  
Grzegorz Górski
Keyword(s):  
Time Series ◽  
Two Phase Flow ◽  
Bubbly Flow ◽  
Flow Patterns ◽  
Recurrence Quantification Analysis ◽  
Phase Flow ◽  
Two Phase ◽  
Signal Characteristics ◽  
Recurrence Quantification ◽  
Quantification Analysis

Abstract The two-phase flow (water-air) occurring in square minichannel (3x3 mm) has been analysed. In the minichannel it has been observed: bubbly flow, flow of confined bubbles, flow of elongated bubbles, slug flow and semi-annular flow. The time series recorded by laser-phototransistor sensor was analysed using the recurrence quantification analysis. The two coefficients:Recurrence rate (RR) and Determinism (DET) have been used for identification of differences between the dynamics of two-phase flow patterns. The algorithm which has been used normalizes the analysed time series before calculating the recurrence plots.Therefore in analysis the quantitative signal characteristicswas neglected. Despite of the neglect of quantitative signal characteristics the analysis of its dynamics (chart of DET vs. RR) allows to identify the two-phase flow patterns. This confirms that this type of analysis can be used to identify the two-phase flow patterns in minichannels.

scholarly journals Flow Patterns Transition Law of Oil-Water Two-Phase Flow under a Wide Range of Oil Phase Viscosity Condition

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Wei Wang ◽  
Wei Cheng ◽  
Kai Li ◽  
Chen Lou ◽  
Jing Gong
Keyword(s):  
Two Phase Flow ◽  
Stratified Flow ◽  
High Viscosity ◽  
Flow Patterns ◽  
Intermittent Flow ◽  
Neutral Stability ◽  
Phase Flow ◽  
Two Phase ◽  
Wide Range ◽  
Oil Water

A systematic work on the prediction of flow patterns transition of the oil-water two-phase flows is carried out under a wide range of oil phase viscosities, where four main flow regimes are considered including stratified, dispersed, core-annular, and intermittent flow. For oil with a relatively low viscosity, VKH criterion is considered for the stability of stratified flow, and critical drop size model is distinguished for the transition of o/w and w/o dispersed flow. For oil with a high viscousity, boundaries of core-annular flow are based on criteria proposed by Bannwart and Strazza et al. and neutral stability law ignoring that the velocity of the viscous phase is introduced for stratified flow. Comparisons between predictions and quantities of available data in both low and high viscosity oil-water flow from literatures show a good agreement. The framework provides extensive information about flow patterns transition of oil-water two-phase flow for industrial application.

scholarly journals Complex networks from multivariate time series for characterizing nonlinear dynamics of two-phase flow patterns

2012 ◽  
Vol 61 (12) ◽  
pp. 120510
Author(s):  
Gao Zhong-Ke ◽  
Jin Ning-De ◽  
Yang Dan ◽  
Zhai Lu-Sheng ◽  
Du Meng
Keyword(s):  
Nonlinear Dynamics ◽  
Time Series ◽  
Complex Networks ◽  
Two Phase Flow ◽  
Multivariate Time Series ◽  
Flow Patterns ◽  
Phase Flow ◽  
Two Phase

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.

Characterization of Two-Phase Flow Patterns in Small Round Tubes

2014 ◽  
Vol 525 ◽  
pp. 256-259
Author(s):  
Wen Peng Hong ◽  
Guo Qing Niu ◽  
Ming Liang Jin
Keyword(s):  
High Speed ◽  
Two Phase Flow ◽  
Flow Characteristics ◽  
Flow Patterns ◽  
Phase Flow ◽  
Two Phase ◽  
High Speed Video ◽  
Video Systems ◽  
Small Tube

To investigate flow characteristics by high speed video systems, experimental study was conducted to gas-liquid two-phase flow in horizontal round small tube with diameter of 5.5 and 2.6 mm, the typical flow pattern images were obtained, but stratified flow of the conventional size horizontal channel had not been discovered. Gas and liquid superficial velocities range from 0.1 to 100 ms-1, and 0.01to 10.0 ms-1 respectively. Flow patterns for co-current flow of air-water mixtures in horizontal round tubes are determined by high-speed video analysis to develop flow regime maps and the transitions between these flow regimes. Comparisons with the relevant literatures show that diameter and surface tension effects play an important role in determining the flow patterns and transitions between them.

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