Heat- mass transfer and flow characteristics of two-phase countercurrent annular flow in a vertical pipe

1998 ◽  
Vol 25 (6) ◽  
pp. 819-829 ◽  
Author(s):  
Somchai Wongwises ◽  
Paisan Naphon
Keyword(s):  
Mass Transfer ◽  
Heat Mass Transfer ◽  
Annular Flow ◽  
Flow Characteristics ◽  
Vertical Pipe ◽  
Two Phase

Parametric study of heat/mass transfer performance of seawater–air two‐phase counterflow in packing in seawater cooling towers

Heat Transfer ◽  
2022 ◽  
Author(s):  
Yang Yu ◽  
Xiao‐Ni Qi ◽  
Xiao‐Chen Hou ◽  
Xiao‐Hang Qu ◽  
Qian‐Jian Guo ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Parametric Study ◽  
Heat Mass Transfer ◽  
Transfer Performance ◽  
Cooling Towers ◽  
Two Phase

Flow Characteristics of Adiabatic Gas-Liquid Two-Phase Flow in a Horizontal Flat Rectangular Microchannel

2011 ◽  
Author(s):  
Hideo Ide ◽  
Kentaro Satonaka ◽  
Tohru Fukano
Keyword(s):  
Void Fraction ◽  
Slug Flow ◽  
Annular Flow ◽  
Two Phase Flow ◽  
Flow Characteristics ◽  
Flow Patterns ◽  
Phase Flow ◽  
Similar Data ◽  
Two Phase ◽  
The Mean

Experiments were performed to obtain, analyze and clarify the mean void fraction, the mean liquid holdup, and the liquid slug velocity and the air-water two-phase flow patterns in horizontal rectangular microchannels, with the dimensions equal to 1.0 mm width × 0.1 mm depth, and 1.0 mm width × 0.2 mm depth, respectively. The flow patterns such as bubble flow, slug flow and annular flow were observed. The microchannel data showed similar data patterns compared to those in minichannels with the width of 1∼10mm and the depth of 1mm which we had previously reported on. However, in a 1.0 × 0.1 mm microchannel, the mean holdup and the base film thickness in annular flow showed larger values because the effects of liquid viscosity and surface tension on the holdup and void fraction dominate. The remarkable flow characteristics of rivulet flow and the flow with a partial dry out of the channel inner wall were observed in slug flow and annular flow patterns in the microchannel of 0.1 mm depth.

Effects of Fin Shapes and Arrangements on Heat Transfer for Impingement/Effusion Cooling With Crossflow

2005 ◽  
Author(s):  
Sung Kook Hong ◽  
Dong-Ho Rhee ◽  
Hyung Hee Cho
Keyword(s):  
Mass Transfer ◽  
Heat Mass Transfer ◽  
Flow Characteristics ◽  
Local Heat ◽  
Wall Jet ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Blowing Ratio ◽  
Transfer Characteristics ◽  
Sublimation Method

The present paper has investigated the effects of fin on the flow and heat/mass transfer characteristics for the impingement/effusion cooling with crossflow. The fins of circular or rectangular shape are installed between two perforated plates and the crossflow passes between these two plates. The blowing ratio is changed from 0.5 to 1.5 for a fixed jet Reynolds number of 10,000. A naphthalene sublimation method is used to obtain the local heat/mass transfer coefficients on the effusion plate. A numerical calculation is also performed to investigate the flow characteristics. Flow and heat/mass transfer characteristics are changed significantly due to installation of fins. In the injection region, wall jet spreads more widely than the case without fins because fin prevents the wall jet from being swept away by the crossflow. In the effusion region, higher heat/mass transfer coefficient is obtained due to the flow disturbance and acceleration by the fin. As the blowing ratio increases, the effects of fin against the crossflow become more significant and then the higher average heat/mass transfer coefficients are obtained. Especially, the cases with rectangular fins have about 40%∼45% enhancement at the high blowing ratio of M = 1.5. However, the increase of blockage effect gives more pressure loss in the channel.

Liquid-Liquid Two-Phase Flow Patterns and Mass Transfer Characteristics in a Circular Microchannel

2012 ◽  
Vol 482-484 ◽  
pp. 89-94
Author(s):  
Xu Bin Zhang ◽  
Dan Chen ◽  
Yan Wang ◽  
Wang Feng Cai
Keyword(s):  
Mass Transfer ◽  
Annular Flow ◽  
Flow Patterns ◽  
Immiscible Fluids ◽  
Viscous Force ◽  
Inertia Force ◽  
Transfer Coefficients ◽  
Two Phase ◽  
Transfer Characteristics ◽  
Circular Microchannel

In this paper, flow patterns and mass transfer characteristics of two immiscible fluids in a T-junction circular microchannel were investigated. Four flow patterns, i.e. slug flow, irregular flow, parallel flow and annular flow, were captured by a CCD method, which were resulted from the competition among interfacial tension, viscous force and inertia force. Besides, the overall volumetric mass transfer coefficients ka for the four flow patterns was determined experimentally. The values of ka are in the range of 0.006~0.545s−1 and mainly dependent on the superficial velocity and the flow pattern regime.

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