Numerical Study of Thethermohydraulic and Energy-saving Performance of a Graphene Nanoplatelet-platinum Hybrid Nanofluid inside a Manifold Microchannel Heat Sink

Due to high heat flux in electronic equipment, the better cooling of these equipment using microchannel heat sink is of interest to many researchers today. However, paying attention to reducing energy consumption is also one of the essential issues that has attracted the attention of researchers and manufacturers.Thermohydraulic characteristics and energy saving of a water-based graphene nanoplatelet-platinum hybrid nanofluid inside a manifold microchannel heat sink for laminar flow have been  investigated numerically for various nanofluid volume fractions (φ=0.02, 0.06, and 0.1%) and Reynolds number (Re=20 to 100). The Properties of hybrid nanofluid were considered temperature-dependent. According to studies conducted in this research, graphene nanoplatelet-platinum hybrid nanofluid in a manifold microchannel heat sink improves heat transfer performance. Cooling uniformity factor as a criterion for diagnosing of hotspot regions decreases with an increase in Reynolds number and nanofluid volume fraction. Nusselt number (Nu) increases with an increase in  the Reynolds and nanofluid volume fraction. Numax=38.10 is obtained for Re=100 and φ=0.1%  and Numin=24.17 is obtained for Re=20 and φ=0. Thermal resistance decreases with an increase in nanofluid volume fraction and Reynolds number. With an increase in Reynolds number andnanofluid volume fraction, pressure drop increases. Also, at low Reynolds numbers (Re=20), pressure drop differences in different volume fractions are insignifcant. For all nanofluid volume fraction values, the performane evaluation criterion (PEC) value is greater than 1, which indicates the improvement of manifold microchannel heat sink efficiency using nanofluids. Also, for all Reynolds values, the performance evaluation criterion with an increase in volume fraction increases. PECmax for Re=20 and φ= 0.02% is achieved. There is no significant difference in the performance evaluation criterion for higher volume concentrations (0.06% and 0.1%) and higher Reynolds numbers (40 to 100).