Development and testing of microchannel heat sink for cooling applications

Abstract

Microchannel heat sink is a promising cooling option (because of larger values of surface area to volume ratio) which can provide higher heat removal rates and may also be integrated directly into the heat dissipation substrate. Heat transfer and fluid flow experiments are conducted with these heat sinks. The experimental results have shown that the heat removed by water increases with increase in flow rate and increase in number of channels. The Nusselt number and heat transfer coefficient are found to increase with flow rate. The experimental result for channel wise flow rate is validated with the predictions of corresponding numerical models. Fluctuations are found in channel wise flow rate for both numerical predictions and experimental results. Manufacturing tolerances are believed to be the primary reason for the fluctuations found in experimental results. In order to study the effect of channel and header parameters, on flow maldistribution, excluding the effect of manufacturing tolerances, it was decided to use FLUENT6.2 based numerical analysis. Numerical models of the present work are validated with the numerical predictions available in the literature, in addition to the experimental validation. Numerical analysis is performed to bring out the effect of channel parameters. The numerical analysis is validated against the results obtained from in-house experimental facility. C-type flow arrangement and I-type flow arrangements have shown better flow distribution. Z-type and V-type have shown larger flow maldistribution due to larger pressure variation between the inlet and outlet headers along the flow direction. The effect of maldistribution on heat transfer is presented by plotting the channel wise averaged fluid temperature. Larger variation in channel wise averaged fluid temperature is reported for air, the reason for the same is attributed to lower value of specific heat capacity. newline newline newline