Flow pattern transition during condensation of R134a and R1234ze(E) in microchannel arrays

2017 ◽  
Vol 115 ◽  
pp. 244-255 ◽  
Author(s):  
Ji Wang ◽  
Jun Ming Li ◽  
Yunho Hwang
Keyword(s):  
Flow Pattern ◽  
Microchannel Arrays ◽  
Flow Pattern Transition

GAS-LIQUID FLOW-PATTERN TRANSITION IN HORIZONTAL PIPES – ANALYSIS OF REPORTED MODELS

2018 ◽  
Author(s):  
André Mendes Quintino ◽  
Davi Lotfi Lavor Navarro da Rocha ◽  
Oscar Mauricio Hernandez Rodriguez
Keyword(s):  
Flow Pattern ◽  
Liquid Flow ◽  
Horizontal Pipes ◽  
Flow Pattern Transition ◽  
Gas Liquid Flow

Spool Valve Hydraulic Measurement Flow Pattern Error Based on Variable Discharge Coefficient

2015 ◽  
Vol 667 ◽  
pp. 444-448
Author(s):  
Zhuo Lin
Keyword(s):  
Flow Pattern ◽  
Discharge Coefficient ◽  
Compensation Method ◽  
Measuring Process ◽  
Important Method ◽  
Flow Pattern Transition ◽  
Spool Valves ◽  
Spool Valve ◽  
Submerged Discharge

Spool valves are the main elements in electro-hydro servo valves. Hydraulic measurement is an important method for spool valve’s null cutting measuring process. Because of the flow pattern transition, the discharge coefficient is a variable. This phenomenon causes errors if we assume the discharge coefficient is a constant as we always do. In this paper, the variable discharge coefficient is considered to the submerged discharge equation, and the flow pattern error is defined. For improving the precision of overlap values measurements, a compensation method of flow pattern error is presented in this paper.

Flow-Pattern Transition and Hydrodynamic Modeling of Churn Flow

SPE Journal ◽  
1999 ◽  
Vol 4 (12) ◽  
Author(s):  
J. Tengesdal ◽  
A.S. Kaya ◽  
Cem Sarica
Keyword(s):  
Flow Pattern ◽  
Hydrodynamic Modeling ◽  
Flow Pattern Transition ◽  
Churn Flow

Detecting the Flow Pattern Transition in the Gas-Liquid Two-Phase Flow Using Multivariate Multi-Scale Entropy Analysis

2019 ◽  
Vol 74 (10) ◽  
pp. 837-848 ◽  
Author(s):  
Yudong Liu ◽  
Dayang Wang ◽  
Yingyu Ren ◽  
Ningde Jin
Keyword(s):  
Flow Pattern ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Mean Value ◽  
Entropy Rate ◽  
Permutation Entropy ◽  
Phase Flow ◽  
Two Phase ◽  
Multi Scale ◽  
Flow Pattern Transition

AbstractDue to the complex flow structure and non-uniform phase distribution in the vertical upward gas-liquid two-phase flow, an eight-electrode rotating electric field conductance sensor is used to obtain multi-channel conductance signals. The flow patterns of the vertical upward gas-liquid two-phase flow are classified according to the images obtained from a high-speed camera. Then, we employ the multivariate weighted multi-scale permutation entropy (MWMPE) to detect the instability of flow pattern transition in the gas-liquid two-phase flow. Afterwards, we compare the results of the MWMPE with those of the single-channel weighted multi-scale permutation entropy (SCWMPE) and multivariate multi-scale sample entropy (MMSE). The comparison results indicate that, compared with the SCWMPE and MMSE, the MWMPE has superior performance in terms of the high-resolution presentation of flow instability in the gas-liquid two-phase flow. Finally, we extract the mean value of the MWMPE in whole scales and the entropy rate of the MWMPE in the small scales. The results indicate that the normalized mean value and normalized entropy rate of MWMPE are very sensitive to the transitions of flow patterns, thus allowing the detection of the instability of flow pattern transition.

Investigation of the Flow Pattern Transition Behaviors of Viscous Oil–Water Flow in Horizontal Pipes

2020 ◽  
Vol 59 (47) ◽  
pp. 20892-20902
Author(s):  
Haili Hu ◽  
Jiaqiang Jing ◽  
Sara Vahaji ◽  
Jiatong Tan ◽  
Jiyuan Tu
Keyword(s):  
Flow Pattern ◽  
Water Flow ◽  
Horizontal Pipes ◽  
Viscous Oil ◽  
Flow Pattern Transition ◽  
Oil Water
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