Modeling of Heat Transfer in Microchannel Gas Flow

Lewandowski, Tomasz; Czerwinska, Justyna; Ochrymiuk, Tomasz (2011). Modeling of Heat Transfer in Microchannel Gas Flow. Journal of heat transfer - transactions of the ASME, 133(2), 022401. New York, N.Y.: American Society of Mechanical Engineers ASME 10.1115/1.4002438

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Due to the existence of a velocity slip and temperature jump on the solid walls, the heat transfer in microchannels significantly differs from the one in the macroscale. In our research, we have focused on the pressure driven gas flows in a simple finite microchannel geometry, with an entrance and an outlet, for low Reynolds (Re<200) and low Knudsen (Kn<0.01) numbers. For such a regime, the slip induced phenomena are strongly connected with the viscous effects. As a result, heat transfer is also significantly altered. For the optimization of flow conditions, we have investigated various temperature gradient configurations, additionally changing Reynolds and Knudsen numbers. The entrance effects, slip flow, and temperature jump lead to complex relations between flow behavior and heat transfer. We have shown that slip effects are generally insignificant for flow behavior. However, two configuration setups (hot wall cold gas and cold wall hot gas) are affected by slip in distinguishably different ways. For the first one, which concerns turbomachinery, the mass flow rate can increase by about 1% in relation to the no-slip case, depending on the wall-gas temperature difference. Heat transfer is more significantly altered. The Nusselt number between slip and no-slip cases at the outlet of the microchannel is increased by about 10%.

Item Type:	Journal Article (Original Article)
Division/Institute:	10 Strategic Research Centers > ARTORG Center for Biomedical Engineering Research > ARTORG Center - Artificial Kidney Research
UniBE Contributor:	Czerwinska, Justyna
ISSN:	0022-1481
Publisher:	American Society of Mechanical Engineers ASME
Language:	English
Submitter:	Factscience Import
Date Deposited:	04 Oct 2013 14:32
Last Modified:	05 Dec 2022 14:10
Publisher DOI:	10.1115/1.4002438
Web of Science ID:	000283936600012
URI:	https://boris.unibe.ch/id/eprint/12237 (FactScience: 218546)