Imperial College London
Portrait Picture

Professor Omar K. Matar, FREng

Faculty of Engineering, Department of Chemical Engineering

Head of Department of Chemical Engineering
 
 
 
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Contact

 

+44 (0)20 7594 9618o.matar Website

 
 
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Assistant

 

Mr Avery Kitchens +44 (0)20 7594 6263

 
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Location

 

305 ACEACE ExtensionSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Municchi:2022:10.1016/j.ijheatmasstransfer.2022.123166,
author = {Municchi, F and El, Mellas I and Matar, OK and Magnini, M},
doi = {10.1016/j.ijheatmasstransfer.2022.123166},
journal = {International Journal of Heat and Mass Transfer},
pages = {123166--123166},
title = {Conjugate heat transfer effects on flow boiling in microchannels},
url = {http://dx.doi.org/10.1016/j.ijheatmasstransfer.2022.123166},
volume = {195},
year = {2022}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - This article presents a computational study of saturated flow boiling in non-circular microchannels. The unit channel of a multi-microchannel evaporator, consisting of the fluidic channel and surrounding evaporator walls, is simulated and the conjugate heat transfer problem is solved. Simulations are performed using OpenFOAM v2106 and the built-in geometric Volume Of Fluid method, augmented with self-developed libraries to include liquid-vapour phase-change and improve the surface tension force calculation. A systematic study is conducted by employing water at atmospheric pressure, a channel hydraulic diameter of  µm, a uniform base heat flux of  , and by varying the channel width-to-height aspect-ratio and channel fin thickness in the range –4 and , respectively. The effects of conjugate heat transfer and channel aspect-ratio on the bubble and evaporative film dynamics, heat transfer, and evaporator temperature are investigated in detail. This study reveals that, when the flow is single-phase, higher Nusselt numbers and lower evaporator base temperatures are achieved for smaller channel aspect-ratios, from  and  when , to  and  when , for same fin thickness . In the two-phase flow regime, Nusselt numbers in the range  are achieved. The trends of the Nusselt number versus the aspect-ratio are non-monotonic and exhibit a marked dependence on the channel fin thickness. For small fin thicknesses,  and , an overall ascending trend of  for increasing aspect-ratios is apparent, although in the narrower range –2 the Nusselt number appears weakly dependent on . For thicker fins,  and , the Nusselt number decreases slightly when increasing the aspect-ratio in the range –2, although this trend is not monotonic when considering the entire range of aspect-ratios investigated. Nonetheless, due to conjugate heat transfer, Nusselt numbers and evaporator base temperatures follow different trends when varying the aspect-ratio, and channels with  seem to promo
AU  - Municchi,F
AU  - El,Mellas I
AU  - Matar,OK
AU  - Magnini,M
DO  - 10.1016/j.ijheatmasstransfer.2022.123166
EP  - 123166
PY  - 2022///
SN  - 0017-9310
SP  - 123166
TI  - Conjugate heat transfer effects on flow boiling in microchannels
T2  - International Journal of Heat and Mass Transfer
UR  - http://dx.doi.org/10.1016/j.ijheatmasstransfer.2022.123166
UR  - https://www.sciencedirect.com/science/article/pii/S0017931022006366?via%3Dihub
UR  - http://hdl.handle.net/10044/1/98841
VL  - 195
ER  -
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