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Nonlinear time‐series analysis of optical signals to identify multiphase flow behavior in microchannels
Author(s) -
Peng Dongyue,
Xin Feng,
Zhang Lexiang,
Gao Zuopeng,
Zhang Weihua,
Wang Yuexing,
Chen Xiaodong,
Wang Yi
Publication year - 2017
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.15584
Subject(s) - flow (mathematics) , mechanics , nonlinear system , multiphase flow , instability , series (stratigraphy) , thermodynamics , volumetric flow rate , two phase flow , bubble , open channel flow , entropy (arrow of time) , statistical physics , mathematics , physics , geology , paleontology , quantum mechanics
This study provides an insight into the instability and irregularity of multiphase flows in microchannels. Using a homemade optical measuring system, time series related to two‐phase flow dynamics under different operating conditions, fluids, and channel lengths were collected and analyzed via a nonlinear characteristic parameter, Kolmogorov entropy (K E ). Our results reveal that higher K E corresponds to unstable flow behavior, while lower K E refers to steady flow behavior; higher K E values appear at comparatively low or high gas flow rates, and most Taylor flow regime appeared at proper operating conditions with small K E . An equation derived based on the definition of K E is proposed to better understand K E characteristics, which include bubble break‐up impact and gas/liquid flow rate ratio. Predictions from the proposed analytical equation agree with experimental results, suggesting that the equation effectively identifies unstable flows and can be used to ensure stable and predictable multiphase flows in microchannels. © 2016 American Institute of Chemical Engineers AIChE J , 63: 2378–2385, 2017