Numerical Study on Taylor Bubble Formation in a Micro-channel T-Junction Using VOF Method

2009 ◽  
Vol 21 (S1) ◽  
pp. 51-58 ◽  
Author(s):  
Fang Guo ◽  
Bin Chen
Author(s):  
Mohamed El Amine Ben Amara ◽  
Patrick Perré ◽  
Abdolreza Kharaghani ◽  
Sassi Ben Nasrallah

Author(s):  
Chun K. Kwok ◽  
Matthew M. Asada ◽  
Jonathan R. Mita ◽  
Weilin Qu

This paper presents an experimental study of single-phase heat transfer characteristics of binary methanol-water mixtures in a micro-channel heat sink containing an array of 22 microchannels with 240μm × 630μm cross-section. Pure water, pure methanol, and five methanol-water mixtures with methanol molar fraction of 16%, 36%, 50%, 63% and 82% were tested. Key parametric trends were identified and discussed. The experimental study was complemented by a three-dimensional numerical simulation. Numerical predictions and experimental data are in good agreement with a mean absolute error (MAE) of 0.87%.


Author(s):  
Woorim Lee ◽  
Gihun Son

Bubble growth on a micro-finned surface, which can be used in enhancing boiling heat transfer, is numerically investigated by solving the conservation equations of mass, momentum, and energy. The bubble deformation or the liquid-vapor interface is determined by the sharp-interface level-set method, which is modified to include the effect of phase change and to treat the contact angle and the evaporative heat flux from the liquid microlayer on an immersed solid surface of a microfin. The numerical method is applied to clarify bubble growth and heat transfer characteristics on a surface including fin and cavity during nucleate boiling which have not been provided from the previous experimental studies. The effects of single fin, fin-cavity distance, and fin-fin spacing on the bubble dynamics are investigated. The micro-fin is found to affect the activation of cavity. The fin-cavity configuration is found to determine the bubble formation in a cavity. The vapor removal rate is also observed to significantly depend on the fin-fin spacing.


Author(s):  
Andrew Quon ◽  
Abdul Ahad Khan ◽  
Navdeep Singh Dhillon

Abstract The physics of transient behavior of liquid drops impacting hot and cold surfaces is of significance in many different applications such as spray cooling, condensation and aircraft icing, and analogous to the process of bubble formation and departure in boiling. The resulting local thermal transients in these processes are primarily dictated by passive parameters such as substrate and liquid thermal properties and flow conditions. We are exploring the use of a surface-embedded phase change material (PCM) to actively manipulate these thermal transients as a means to enhance overall heat transfer performance. The thermal effect of the embedded PCM can be parametrically studied using controlled drop impact experiments. In this work, we perform an analytical and numerical study to model the effect of a liquid drop impacting a hot PCM-embedded substrate. By solving an analytical heat transfer solidification problem, we study the effect of PCM properties and PCM initial temperature on the thermal transients encountered during drop impact. Further, we validate the numerical analysis by showing agreement with experimental results.


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