Abstract
A numerical study to compare the performance of water and copper oxide (CuO) nanofluid flowing under laminar regime in a parallel-plate channel, serving as a heat sink in an electronic device, has been presented. The geometry considered here is commonly used in the design of heat sinks suitable for cooling an array of microprocessor chips for which air cooling is insufficient. The influence of nanofluids concentration on local and average skin friction coefficients, Nusselt numbers, and convective heat-transfer coefficients in the channel have been analyzed in detail. The increases in the skin friction and heat transfer with volumetric concentration of nanoparticles have been evaluated from numerical simulations in the Reynolds number range of 100 to 2000. The analysis shows that the flow in this heat sink is hydrodynamically and thermally developing, for which the axial variations of local skin friction and local Nusselt number are presented. As an example, computational results for an 8 % volumetric concentration of CuO nanofluid shows that at a Reynolds number of 2000, the average heat-transfer coefficient increases nearly by a factor of 2 in comparison with pure water. From a detailed analysis summarized in Table 2, it is observed that there is an increase in the pressure loss as the particle concentration increases. For the CuO nanofluid of dilute concentration of 2 %, a slightly higher pumping power of about 10 % compared to water is predicted. This may be tolerable for the thermal protection of expensive electronic chips, in applications where the chip cost is the dominant factor.
