Investigation On Flow Characteristics And Heat Transfer In A Manifold Micro-Channel Heat Sink

As miniaturization, reduction in products weight, high power have become the latest trend in electronic products development, traditional design methods and manufacturing technology fail to meet today's demands. Of the currently available coolers for electronic products with a high heat flux, microchannel heat sinks have been proved to be able to provide the best heat transfer performance and are one of the most promising coolers. The manifold microchannel (MMC) heat sink has many advantages such as low thermal resistance, compact structure, little amount of coolant, low flow rate, uniform temperature distribution along the flow direction and many others, so it is able to provide the best heat transfer performance: lowering the maxmal temperature and the temperature difference.In this paper, a MMC heat sink is fabricated and processed according to the results of numerical optimization of a MMC heat sink firstly, then thoroughly studies its flow characteristics and heat transfer characteristics by experimental methods, and de-ionized water and surfactant aqueous solution are used as working fluids.The experimental results of the flow characteristics of the MMC heat sink indicate that the critical Reynolds number signifying the transition from laminar flow to turbulent flow is in advance; under the same experimental conditions, the variation in entrance direction of the microchannel inlet and outlet has little effect on the microchannel; the experimental values of the friction factor of the de-ionized water in a microchannel agree well with those calculated using the theoretical laminar formula;furthermore, a comparison of the experimental results and simulation results shows that Navier-Stokes equation and RNGκ-εturbulence model can be used to model the laminar and turbulence flow regions in a microchannel; meanwhile, the correlations of the flow resistance in the turbulent flow regions for the de-ionized water as the working fluids are obtained from experiments.Moreover,this paper investigates the influences of surfactant aqueous solutions on flow characteristics of a MMC. Sodium Dodecyl Sulphate aqueous solution and Alkyl Polyglycoside aqueous solution are used as working fluids. The experiment results indicate that the drag reduction depends on flow velocity and temperature; the drag reduction effects aren't very obvious in laminar flow region, but when fluid enter turbulent flow region, the drag reduction increase notably, the drag reduction effects...