Effect of wall surface wettability on pressure drop of gas-liquid two-phase flow in horizontal rectangular micro-channel

2018 ◽  
Vol 2018.71 (0) ◽  
pp. A32
Author(s):  
Takuya MIYAZAKI ◽  
Yukihiro YONEMOTO ◽  
Kojiro MITSUYASU ◽  
Akimaro KAWAHARA
Keyword(s):  
Pressure Drop ◽  
Two Phase Flow ◽  
Surface Wettability ◽  
Phase Flow ◽  
Micro Channel ◽  
Wall Surface ◽  
Two Phase

Two-Phase Flow and Heat Transfer in Rectangular Micro-Channels

2003 ◽  
Author(s):  
Weilin Qu ◽  
Seok-Mann Yoon ◽  
Issam Mudawar
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Flow Pattern ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Heat Sinks ◽  
Phase Flow ◽  
Micro Channel ◽  
Two Phase ◽  
Micro Channels

Knowledge of flow pattern and flow pattern transitions is essential to the development of reliable predictive tools for pressure drop and heat transfer in two-phase micro-channel heat sinks. In the present study, experiments were conducted with adiabatic nitrogen-water two-phase flow in a rectangular micro-channel having a 0.406 × 2.032 mm cross-section. Superficial velocities of nitrogen and water ranged from 0.08 to 81.92 m/s and 0.04 to 10.24 m/s, respectively. Flow patterns were first identified using high-speed video imaging, and still photos were then taken for representative patterns. Results reveal that the dominant flow patterns are slug and annular, with bubbly flow occurring only occasionally; stratified and churn flow were never observed. A flow pattern map was constructed and compared with previous maps and predictions of flow pattern transition models. Annual flow is identified as the dominant flow pattern for conditions relevant to two-phase micro-channel heat sinks, and forms the basis for development of a theoretical model for both pressure drop and heat transfer in micro-channels. Features unique to two-phase micro-channel flow, such as laminar liquid and gas flows, smooth liquid-gas interface, and strong entrainment and deposition effects are incorporated into the model. The model shows good agreement with experimental data for water-cooled heat sinks.

Two-Phase Flow and Heat Transfer in Rectangular Micro-Channels

2004 ◽  
Vol 126 (3) ◽  
pp. 288-300 ◽  
Author(s):  
Weilin Qu ◽  
Seok-Mann Yoon ◽  
Issam Mudawar
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Flow Pattern ◽  
Two Phase Flow ◽  
Flow Boiling ◽  
Flow Patterns ◽  
Heat Sinks ◽  
Phase Flow ◽  
Micro Channel ◽  
Two Phase

Knowledge of flow pattern and flow pattern transitions is essential to the development of reliable predictive tools for pressure drop and heat transfer in two-phase micro-channel heat sinks. In the present study, experiments were conducted with adiabatic nitrogen-water two-phase flow in a rectangular micro-channel having a 0.406×2.032mm2 cross-section. Superficial velocities of nitrogen and water ranged from 0.08 to 81.92 m/s and 0.04 to 10.24 m/s, respectively. Flow patterns were first identified using high-speed video imaging, and still photos were then taken for representative patterns. Results reveal the dominant flow patterns are slug and annular, with bubbly flow occurring only occasionally; stratified and churn flow were never observed. A flow pattern map was constructed and compared with previous maps and predictions of flow pattern transition models. Features unique to two-phase micro-channel flow were identified and employed to validate key assumptions of an annular flow boiling model that was previously developed to predict pressure drop and heat transfer in two-phase micro-channel heat sinks. This earlier model was modified based on new findings from the adiabatic two-phase flow study. The modified model shows good agreement with experimental data for water-cooled heat sinks.

Pressure Drop on Liquid Transportation Using the Characteristics of Gas-Liquid Two-phase Flow in Micro Channel

2002 ◽  
Vol 2002 (0) ◽  
pp. 83-84
Author(s):  
Masahiro AWANE ◽  
Takashi KURAMOTO ◽  
Kenji YOSHIDA ◽  
Tadayoshi MATSUMOTO ◽  
Tomio OKAWA ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Micro Channel ◽  
Two Phase

E-10 Pressure drop for gas and non-Newtonian liquid two-phase flow in micro-channel

2016 ◽  
Vol 2016.69 (0) ◽  
pp. 191-192
Author(s):  
Akifumi MORI ◽  
Akimaro KAWAHARA ◽  
Yukihiro YONEMOTO ◽  
Michio SADATOMI
Keyword(s):  
Pressure Drop ◽  
Two Phase Flow ◽  
Newtonian Liquid ◽  
Phase Flow ◽  
Micro Channel ◽  
Two Phase

Effect of surface wettability on pressure drop in single and two-phase flow

2003 ◽  
Vol 2003 (0) ◽  
pp. 349-350
Author(s):  
Yuta UCHINO ◽  
Yasuyuki TAKATA ◽  
Sumitomo HIDAKA ◽  
Tadamichi NAKAMURA
Keyword(s):  
Pressure Drop ◽  
Two Phase Flow ◽  
Surface Wettability ◽  
Phase Flow ◽  
Two Phase ◽  
Effect Of Surface

Numerical Simulation on Pressure Drops for Air-Water Two-Phase Flow in Micro-Channels

2008 ◽  
Author(s):  
Hao Peng ◽  
Xiang Ling
Keyword(s):  
Experimental Data ◽  
Pressure Drop ◽  
Two Phase Flow ◽  
Vof Method ◽  
Phase Flow ◽  
Micro Channel ◽  
Two Phase ◽  
Pressure Drops ◽  
Micro Channels ◽  
Phase Pressure

Rigorous two-phase flow modeling is one of the great challenges in the thermal sciences. A two-dimensional computational fluid dynamics (CFD) simulation of air-water two-phase pressure drop characteristics in micro-channels by using volume of fluid (VOF) method was carried out in this paper. The simulations were performed in a horizontal micro-channel with a diameter of 1.1 mm and a length of 200 mm. Firstly, a variety of air-water two-phase flow patterns (including bubbly, slug, slug-annular and annular flow) were simulated in order to validate the feasibility and reliability of the VOF method. Next to that, the two-phase pressure drops in micro-channel were analyzed numerically by using the same CFD method. Also the comparison of pressure drop among the numerical simulations, experimental data and the results calculated by homogeneous equilibrium model was presented. The agreement between numerical results and the existing experimental data was found to be satisfactory. Based on this good agreement, it is finally found that the numerical analysis procedure proposed in this paper can be used to achieve a better prediction for micro-channel air-water flow characteristics.

scholarly journals Capillarity Effect on Two-Phase Flow Resistance in Microchannels

2007 ◽  
Author(s):  
Prakash Rapolu ◽  
Sang Young Son
Keyword(s):  
Pressure Drop ◽  
High Speed ◽  
Energy Surface ◽  
Two Phase Flow ◽  
Surface Wettability ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Pressure ◽  
Set Up ◽  
Phase Water

An experimental set-up is developed to investigate the effects of surface energy/surface wettability on characteristics of two-phase flow in microchannels. Two-phase (water and air) slug flow is established in entrance effect free microchannel test sections of various surface wettabilities. Pressure drop measurements and flow pattern detection by high speed visualization are employed to characterize the flow. Pressure drop of flow in hydrophilic channels is lesser than that of flow in hydrophobic channels. Significant change in contact line in advancing and receding interface section with surface wettability is observed.

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