Entropy Generation Minimization of Microchannel Heat sink Using Nanofluids as a Coolant

The continuous effort to produce more powerful and small electronic device is making the controlling of thermal and fluid design process of the cooling system very difficult. Analysing the required data for designing a microchannel heat sink cooled by nanofluids also become a challenge. One of these methods of data calculation is called “Entropy Generation”, which determines the rate of irreversibility. Since “irreversibility” is a measure of the unconventionality to the ideal cases, so it is better to be minimized in all thermal process. In this study, the use of nanofluids as a coolant for cooling electronic devices has been studied using entropy generation minimization. The advanced mathematical model has been developed for calculating both thermal and frictional entropy generation. The investigation was performed for Al2O3 nanoparticles with two base fluids, Water and Ammonia. The results demonstrated that in terms of entropy generation and pressure drop, the water base nanofluid obtained a (6.45% and 3.89%) reduction, respectively, while for the same Al2O3 nanoparticle with ammonia base fluid a reduction of (73.8%) for entropy generation and (65.8%) pressure drop were achieved. Furthermore, the optimum channel aspect ratio was (0.31) for all three type of fluid. In addition, ammonia base nanofluid reduced the pumping power under the same circumstances by (65%) compared to the pure water as a coolant. Based on the results obtained in this study, ammonia base nanofluid should be considered as the future coolant for electronic devices cooling systems.