Heat transfer and flow issues in manifold microchannel heat sinks: a CFD approach

Advances in microfabrication technology have allowed the use of microchannels in ultra compact, very efficient heat exchangers, which capitalize on the channel´s large surface area to volume ratio to transport high heat fluxes with small thermal resistances. One example is the cooling of microchips. However, the research into microscale flow and heat transfer phenomena conducted by various researchers provided substantial experimental data and considerable evidence that the behaviour of fluid flow and heat transfer in microchannels without phase change may be different than that which normally occurs in larger more conventionally sized channels. This paper serves to perform a numerical analysis of flow and heat transfer in manifold microchannels. A numerical model for 16 sets of parametric conditions was created using the ANSYS CFD package. Pressure, temperature and velocity contour plots were obtained and analyzed. The results obtained were then compared with a derived analytical model. The predictions showed a large dependence on flow rate. Differences in values and trends were expected as the analytical model assumed a straight channel unlike a manifold channel. Further comparisons were also made regarding the relationship between the Reynolds number and the friction factor. Data were also compared with the research of another author using FLUENT software