Conjugate heat transfer effects on flow boiling in microchannels
نویسندگان
چکیده
This article presents a computational study of saturated flow boiling in non-circular microchannels. The unit channel multi-microchannel evaporator, consisting the fluidic and surrounding evaporator walls, is simulated conjugate heat transfer problem solved. Simulations are performed using OpenFOAM v2106 built-in geometric Volume Of Fluid method, augmented with self-developed libraries to include liquid-vapour phase-change improve surface tension force calculation. A systematic conducted by employing water at atmospheric pressure, hydraulic diameter Dh=229 µm, uniform base flux qb=100 kW/m2, varying width-to-height aspect-ratio fin thickness range ?=0.25–4 Wf=Dh/8?Dh, respectively. effects on bubble evaporative film dynamics, transfer, temperature investigated detail. reveals that, when single-phase, higher Nusselt numbers lower temperatures achieved for smaller aspect-ratios, from Nu?4 Tb?Tsat?9K ?=4, Nu?6 Tb?Tsat?2K ?=0.25, same Wf=Dh/8. In two-phase regime, Nu=12?36 achieved. trends number versus non-monotonic exhibit marked dependence thickness. For small thicknesses, Wf=Dh/8 Wf=Dh/4, an overall ascending trend Nu increasing aspect-ratios apparent, although narrower ?=0.5–2 appears weakly dependent ?. thicker fins, Wf=Dh/2 Wf=Dh, decreases slightly ?=0.5–2, this not monotonic considering entire investigated. Nonetheless, due follow different aspect-ratio, channels ?<1 seem promote than conduits.
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ژورنال
عنوان ژورنال: International Journal of Heat and Mass Transfer
سال: 2022
ISSN: ['1879-2189', '0017-9310']
DOI: https://doi.org/10.1016/j.ijheatmasstransfer.2022.123166