Numerical analysis of mono and hybrid nanofluids-cooled micro finned heat sink for electronics cooling-(Part-II)

Abstract

This study investigates the thermal and hydraulic performance of heat sinks with micro pin-fins in circular and rectangular configurations using mono and hybrid nanofluids. Motivated by the need for efficient cooling solutions in high-performance electronic devices, the research explores novel combinations of metallic oxide (Ag, MgO) and carbon-based nanoparticles (GNP, MWCNT) in nanofluids. A constant volume fraction of micro pinfins and nanoparticles was maintained to assess their effects on thermohydraulic performance. The method involved experiments with aqueous nanofluids as coolants, measuring pressure drops (Δp) at the inlet and outlet. Thermal performance was evaluated using metrics like thermal resistance (Rth), Nusselt number (Nuavg), pumping power (PP), volumetric flow rate (Q), overall performance (OP), and performance evaluation criterion (PEC). Results showed that GNP-based mono nanofluids significantly reduced Rth by 46.41% and increased Nuavg by 60.54% and PEC by 62% in rectangular heat sinks compared to conventional water cooling. Comparisons between rectangular and circular configurations revealed minimal Rth differences of 2.54% and 3.57%. GNPdispersed nanofluids outperformed other coolants, with the rectangular configuration achieving a higher PEC of 1.62 versus 1.52 for the circular configuration at Δp = 820 Pa. The conclusions suggest that rectangular pinfins with GNP-based nanofluids offer superior thermohydraulic performance. The key outcomes from current study have significant contribution in enhancing the cooling efficiency of advanced electronic systems.