Single-phase liquid flow forced convection under a nearly uniform heat flux boundary condition in microchannels

Type
Article

Authors
Lee, Man
Lee, Yi-Kuen
Zohar, Yitshak

KAUST Grant Number
SA-C0040/UK-C0016

Online Publication Date
2012-02-22

Print Publication Date
2012-03-01

Date
2012-02-22

Abstract
A microchannel heat sink, integrated with pressure and temperature microsensors, is utilized to study single-phase liquid flow forced convection under a uniform heat flux boundary condition. Utilizing a waferbond-and-etch- back technology, the heat source, temperature and pressure sensors are encapsulated in a thin composite membrane capping the microchannels, thus allowing experimentally good control of the thermal boundary conditions. A three-dimensional physical model has been constructed to facilitate numerical simulations of the heat flux distribution. The results indicate that upstream the cold working fluid absorbs heat, while, within the current operating conditions, downstream the warmer working fluid releases heat. The Nusselt number is computed numerically and compared with experimental and analytical results. The wall Nusselt number in a microchannel can be estimated using classical analytical solutions only over a limited range of the Reynolds number, Re: both the top and bottom Nusselt numbers approach 4 for Re < 1, while the top and bottom Nusselt numbers approach 0 and 5.3, respectively, for Re > 100. The experimentally estimated Nusselt number for forced convection is highly sensitive to the location of the temperature measurements used in calculating the Nusselt number. © 2012 IOP Publishing Ltd.

Citation
Lee M, Lee Y-K, Zohar Y (2012) Single-phase liquid flow forced convection under a nearly uniform heat flux boundary condition in microchannels. Journal of Micromechanics and Microengineering 22: 035015. Available: http://dx.doi.org/10.1088/0960-1317/22/3/035015.

Acknowledgements
This work is supported by a grant from Hong Kong Research Grants Council (Grant No 616106) and partially supported by a grant from King Abdullah University of Science and Technology (KAUST Award No SA-C0040/UK-C0016).

Publisher
IOP Publishing

Journal
Journal of Micromechanics and Microengineering

DOI
10.1088/0960-1317/22/3/035015

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