Design And Numerical Study Of Microchannel Heat-Sink

The recent trend in the electronic equipment industry is toward denser and more powerful, this requires higher thermal performance cooling technique to adapt to. Many ideas for innovative cooling methods have been proposed including a microchannel heat sink. A micro-channel heat sink, as first proposed by Tuckerman and Pease, is based on the idea that the heat transfer coeffcient is inversely proportional to the hydraulic diameter of the channel. Even though the microchannel heat sink has brought significant improvements in the cooling performance, it has not been widely used because of two limitations:a high pressure drop due to a small hydraulic diameter of the channel and a significant temperature variation within the heat source between inlet and outlet. In this thesis, a3-D numerical study on the flow and heat transfer of four kinds of rectangular microchannel heat sinks is conducted. The rationality of the simulation methods and results were validated by comparing with experimental data, proved that the Navier-Stokes equation and energy equation can accurately describe the fluid flow and heat transfer characteristics of microchannel. In order to obtain a higher performance microchannel heat sink, this paper presents a ladder type microchannel heat sink, and a corresponding comparison between parallel microchannels.heat sink and ladder type microchannel heat sink was made. For the pressure drop of single-layer microchannel heat sink is too huge, stacked microchannel heat sinks which can solve this problem is studied. Through the comparison between double microchannel heat sink and single layer of microchannel heat sink, the advantage of stacked microchannel heat sink is proved. Then the effect of flow arrangement on stacked microchannel heat sink performance is researched, and taking double microchannel heat sink as example the influence of interlayer flow distribution was analyzed. According to the heat transfer characteristics of counter flow type of double microchannel heat sink, an improvement was carried. Finally, this article does some researches on nanofluid microchannel heat sink. Calculation formulas which can be accurately described nano fluid properties were selected, and the formulas accuracy were validated by comparing with experimental data. Using this model the research on nanofluids microchannel heat sink was launched, the influences of nano particle type, particle diameter and the particle volume fraction on the microchannel heat sink performance were discussed.