Thermohydraulic performance improvement and entropy generation characteristics of a microchannel heat sink cooled with new hybrid nanofluids containing ternary/binary hybrid nanocomposites

Abstract

Abstract Recently, the combination of hybrid nanofluids with microchannel heat sinks (MCHSs) has led to superior heat removal from high heat flux electronics chips. The present work aimed to evaluate numerically the first and second law performances of MCHSs using the new cost‐effective binary/ternary hybrid nanofluids. Water‐based binary and ternary hybrid nanofluids include the MgO/TiO2 nanocomposite and the CuO/MgO/TiO2 nanocomposite, respectively. The effects of the hybrid nanofluid volume concentration (vol.%) and Reynolds number (Re) on the heat transfer, pressure drop, combined thermohydraulic characteristics, and entropy generation characteristics of the MCHSs are discussed. The results show that higher values of the convective heat transfer coefficient, pressure drop, and frictional entropy generation rate are obtained when using hybrid nanofluids with high Re and vol.% values. Furthermore, by increasing the Re and vol.% values of the hybrid nanofluids, the bottom wall temperature, total thermal resistance, and thermal entropy generation rate decreased, and an increased temperature uniformity was obtained on the bottom surface of the MCHSs. In conclusion, the applied hybrid nanofluids are considered to be more promising heat transfer fluids when compared with conventional fluids such as water. Particularly, the CuO/MgO/TiO2‐water ternary hybrid nanofluid exhibited a better heat transfer efficiency than did the MgO/TiO2‐water binary hybrid nanofluid.

Keywords

• electronics cooling
• entropy generation
• microchannel heat sink
• ternary hybrid nanofluids
• thermal management
• thermohydraulic performance