A comparison of mixed convective heat transfer performance of nanofluids cooled heat sink with circular perforated pin fin

Abstract

This paper presents a numerical study on the mixed convection of nanofluids in heat sinks with perforated circular fins. Four different types of nanofluids are used as cooling fluids, which are TiO2, Al2O3 and Cu dispersed in pure water as the base fluid. The selected volumetric concentration of nanofluids was chosen in the range (2–10)%. The Reynolds number has changed in the range of 100–400 to ensure that flow remains in the laminar regime and to have the Richardson number 1 ≤ Ri ≤ 22. To study the cooling performance of the heat sink, three-dimensional steady Navier Stokes and energy equations were discretized by the finite volume method using the power-law scheme and have been solved iteratively, using the SIMPLE algorithm. The results show that a significant improvement in heat transfer in the heat sink due to the suspension of nanoparticles in the base fluid compared to pure water, the improvement in heat transfer is intensified with increased Reynolds number and decrease in the volume fraction of nanoparticles. We also found that the low values of the average Nusselt number are obtained for the nanofluid TiO2, the average values for Al2O3 and the highest values for Cu. It is important to note that a slight increase in friction factor and pumping power has been reported when nanofluid is used in the system.