Prediction of Slug-to-Annular Flow Pattern Transition (STA) for Reducing the Risk of Gas-Lift Instabilities and Effective Gas/Liquid Transport From Low-Pressure Reservoirs

2007 ◽  
Vol 22 (03) ◽  
pp. 339-346
Author(s):  
Peter R. Toma ◽  
Edinson Vargas ◽  
Ergun Kuru
Keyword(s):  
Flow Pattern ◽  
Annular Flow ◽  
Low Pressure ◽  
Liquid Transport ◽  
Flow Pattern Transition ◽  
Gas Lift

An Experimental Study on Air-Water Two-Phase Flow Patterns in Pebble Beds

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Bai Bofeng ◽  
Liu Maolong ◽  
Su Wang ◽  
Zhang Xiaojie
Keyword(s):  
Experimental Study ◽  
Flow Pattern ◽  
Test Section ◽  
Slug Flow ◽  
Annular Flow ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Pattern Transition

An experimental study was conducted on the air-water two-phase flow patterns in the bed of rectangular cross sections containing spheres of regular distribution. Three kinds of glass spheres with different diameters (3 mm, 6 mm, and 8 mm) were used for the establishment of the test section. By means of visual observations of the two-phase flow through the test section, it was discovered that five different flow patterns occurred within the experimental parameter ranges, namely, bubbly flow, bubbly-slug flow, slug flow, slug-annular flow, and annular flow. A correlation for the bubble and slug diameter in the packed beds was proposed, which was an extended expression of the Tung/Dhir model, Jamialahmadi’s model, and Schmidt’s model. Three correlations were proposed to calculate the void friction of the flow pattern transition in bubble flow, slug flow, and annular flow based on the bubble model in the pore region. The experimental result showed that the modified Tung and Dhir model of the flow pattern transition was in better agreement with the experimental data compared with Tung and Dhir’s model.

Flow pattern transition and heat transfer of inverted annular flow

1989 ◽  
Vol 15 (5) ◽  
pp. 767-785 ◽  
Author(s):  
N. Takenaka ◽  
T. Fujii ◽  
K. Akagawa ◽  
K. Nishida
Keyword(s):  
Heat Transfer ◽  
Flow Pattern ◽  
Annular Flow ◽  
Flow Pattern Transition

Numerical research on relationship between flow pattern transition and condensation heat transfer in microchannel

2014 ◽  
Vol 31 (5) ◽  
pp. 939-956 ◽  
Author(s):  
Dongliang Sun ◽  
Jinliang Xu ◽  
Peng Ding
Keyword(s):  
Heat Transfer ◽  
Flow Pattern ◽  
Annular Flow ◽  
Condensation Heat Transfer ◽  
Condensation Process ◽  
Content Type ◽  
Flow Pattern Transition ◽  
Circular Microchannel ◽  
Numerical Research ◽  
And Control

Purpose – Based on the numerical research on the relationship between the flow pattern transition and the condensation heat transfer in circular microchannels, the purpose of this paper is to bring forward a concept of external separation circular microchannel to regulate and control the flow pattern for enhancing the condensation heat transfer. Design/methodology/approach – The numerical research is based on the volume of fluid method and the vapor-liquid phase change model proposed by the present authors. Findings – By numerical research on the condensation process of water in a general circular microchannel, it is discovered that, with the increase of the inlet velocity and the reduction of the temperature difference between the saturation temperature and the channel wall temperature, the bubble detachment frequency is raised and the water vapor condensation length is extended, representing an exponential growth. Therefore, for the condensation process with low temperature difference and high mass flow rate, it is in urgent need to regulate and control the flow pattern. Originality/value – To prevent the flow pattern in the general circular microchannel converted from annular flow to slug flow and then to bubble flow, this paper brings forward a concept of external separation circular microchannel, which regulates and controls the flow pattern by discharging partial liquid from the annular wall opening. After regulation and control, the flow pattern is converted from original periodic annular flow/slug flow/bubble flow to current stable annular flow. Accordingly, the heat transfer performance is enhanced and the condensation length is lowered remarkably.

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