Computational and experimental studies on the thermal performance of synthesized composite nanofluid in rectangular microchannel heat sink

• Hydrothermal synthesis of Composite nanofluids (CNF) containing ternary nanocomposite. • CNF has superior thermophysical properties than conventional hybrid nanofluids (HNF). • CFD analysis and fabrication of Rectangular Microchannel Heat Sink. • CNF has a 24% enhanced convective heat transfer coefficient, compared to 14% for HNF. • Reduced base temperature (10°C) and reduced thermal resistance (40%) for CNF. The current work involves the synthesis of novel composite nanofluid (CNF) and the evaluation of their thermal performance as coolant in a rectangular microchannel heat sink (RMCHS). The research work combines numerical simulations and experimental validation. The RMCHS, designed with 18 channels of 400-micron width, facilitates the laminar flow of synthesized CNF, containing Silver (Ag) – Graphene oxide (GO) and multi-walled carbon nanotubes (CNT). In this study, the flow characteristics and thermal performance of the RMCHS were analyzed using Computational Fluid Dynamics (CFD) and compared with the experimental results. The synthesized CNF was evaluated for its stability and morphology, and its thermophysical properties were appraised. The performance of CNF in the removal of heat from the sink was studied and compared with the conventional hybrid nanofluids (HNF), against key parameters such as convective heat transfer coefficient (HTC), the base temperature, and thermal resistance. The findings reveal CNF to be more effective in heat dissipation with a 24% enhanced HTC when compared to water, as against the 14% obtained for HNF. The base temperature was reduced by 10°C with CNF, whereas HNF led to a 4°C reduction, both compared to water. The thermal resistance, was significantly lower for CNF (0.0101 K/W), by almost 40% than the HNF (0.0163 K/W). These results highlight the superior heat dissipation potential of the CNF, making it an assuring choice for use in improved microchannel designs to address electronic chip cooling.