Performance Analysis of Electronics Cooling using Nanofluids in Microchannel Heat Sink

Abstract

Abstract-Performance analysis of thermal enhancement for cooled microchannel heat sink (MCHS) using nanofluidsmathematical formulation was investigated and presented in this paper. Heat transfer capability in terms of thermal conductivity, heat transfer coefficient, thermal resistance, heat flux and required pumping power were evaluated on the effectiveness of copper oxide (CuO), silicon dioxide (SiO 2 ) and titanium dioxide (TiO 2 ) with water as a base fluid. The results showed that thermal performance augmented by 12.2% in thermal conductivity at particle volume fraction of 4% to CuO-water nanofluid, 11.8% for SiO 2 -water and 10.0% for TiO 2 -water. The maximum heat transfer coefficient enhances of 12.4% for CuO, SiO 2 is 8. In the last three decades, the emergence of nanotechnologyis rapidly approaching, were utilized to improve the heat transfer rate to apply on the electronicdevices in order to reach a satisfactory level of thermal efficiency. The heat transfer rate can passively be improved by changing the geometry's flow, boundary conditions or by improving thermo physical properties such as increasing the thermal conductivity of fluid [1]. To meet the high dissipation rate requirements and maintain a low junction temperature in electronic devices, many cooling technologies have been pursued. Among of these, the microchannel heat sink (MCHS) was introduced because of its ability to produce high heat transfer coefficient, small size and volume per heat load and small coolant requirements [2].Working fluids was applied to enhance the heat transfer by changing the fluid transport properties and flow features in MCHS. Recently, this concept has focused on heat transfer enhancement by using a nanofluid that has a nanoscale metallic or non-metallic particles in the base fluids.Besides, nanofluids has become a concern because they display higher potential as heat transfer fluid than normally utilized base fluids and micron sized particle-fluids. This is due to clogging in pumping and flow apparatus which is caused by rapid settling of the micron sized particle. Nanofluids do not indicate this behavior. This makes nanofluids a better choice as heat transfer fluid [3]. Nanofluids (1-100nm-size particles), often called as ultra-fine solid particles, engineered colloidal suspension, are stable and prepared by dispersing a certain percentage of nanoparticles in base fluids [4][5][6].The factors that causes heat transfer enhancement are solid particles and host fluids chemical composition, size, shape and concentration of nanoscale particles, thermal condition and surfactants. Some of these factors also affect the stability of the nanofluids. There are three strategies to attain good stability, namely addition of surfactants, pH control and ultrasonification [7]. From the literature, heat transfer coefficient depends on Reynolds number, volume fraction of the nanofluids (concentration), temperature, base-fluid