THERMAL SCIENCE

International Scientific Journal

Thermal Science - Online First

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Heat transfer and flow structure through a backward-and forward-facing step micro-channels equipped with obstacles

ABSTRACT
This study presents two-dimensional simulations of a flow-through a sudden expansion/contraction micro-channel with the existence of obstacles. The bottom wall is maintained at constant flux, while the other walls are adiabatic. Rectangular adiabatic obstacles are mounted before the expansion region on the upper and lower wall of the channel used. The finite element method was used to discretize the equations that govern the physical model. Results indicate the apparition of a separate vortex, situated in the corner after the sudden expansion of the microchannel for low Reynolds numbers. For higher values and expansion ratios, the vortex separation length increases. The obtained results show that the obstacles have a considerable effect on the dynamics of the flow and enhancement of heat transfer.
KEYWORDS
PAPER SUBMITTED: 2020-02-15
PAPER REVISED: 2020-06-23
PAPER ACCEPTED: 2020-07-16
PUBLISHED ONLINE: 2020-08-08
DOI REFERENCE: https://doi.org/10.2298/TSCI200215219H
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