| Effect of channel and plenum aspect ratios on the performance of microchannel heat sink under different flow arrangements
S. S. Sehgal, Krishnan Murugesan* and S. K. Mohapatra
The Journal of Mechanical Science and Technology, vol. 26, no. 9, pp.2985-2994, 2012
Abstract : Microchannels based heat sinks are considered as potential thermal management solution for electronic devices. The overall thermal
performance of a microchannel heat sink depends on the flow characteristics within microchannels as well as within the inlet and outlet
plenum and these flow phenomena are influenced by channel aspect ratio, plenum aspect ratio and flow arrangements at the inlet and
outlet plenums. In the present research work an experimental investigation has been carried out to understand how the heat transfer and
pressure drop attributes vary with different plenum aspect ratio and channel aspect ratio under different flow arrangements. For this purpose
microchannel test pieces with two channel aspect ratios, 4.72 and 7.57 and three plenum aspect ratios, 2.5, 3.0 and 3.75 have been
tested under three flow arrangements, namely U-, S- and P-types. Test runs were performed by maintaining three constant heat inputs,
125 W, 225 W and 375 W in the range 224.3 ≤ Re ≤ 1121.7. Reduction in channel width (increase in aspect ratio, defined as depth to
width of channel) in the present case has shown about 126 to 165% increase in Nusselt number, whereas increase in plenum length (reduction
in plenum aspect ratio defined as width to length of plenum) has resulted in 18 to 26% increase in Nusselt number.
Keyword : Channel aspect ratio; Flow arrangements; Microchannel heat sink; Nusselt number; Plenum aspect ratio; Pressure drop |
