Influence of carbon-based hybrid nanofluids (GnP + MWCNT/H₂O) on the heat transfer and entropy generation analysis for electronic cooling applications: an experimental study

The present article examined the thermophysical characteristics of functionalized carbon-based hybrid nanomaterials dispersed in H₂O and EG, and studied the optimal combination for cooling electronic chips in a heat sink. Nanomaterials selected were functionalized graphene nanoplatelets (f-GnP) and multiwalled carbon nanotubes (f-MWCNT) mixed in the ratio of 1:1. The carbon-based hybrid nanofluids have been produced by a 2-step technique with vol% ranging from 0.1% to 1%. The thermophysical properties of carbon-based hybrid nanofluids were examined with standard techniques for the temperatures of 20 °C–60 °C in steps of 10 °C. The improvement of ∼100% and 246% for H₂O-based hybrid nanofluids in thermal conductivity and thermal diffusivity was detected, while it was ∼95% and 152% for EG-based hybrid nanofluids at 1 vol%. The H₂O-based hybrid nanofluids were advantageous in the laminar region for the entire vol% from the predicted effectiveness. Furthermore, the best-performing H₂O-based hybrid nanofluids were studied in a microchannel heat sink for electronic cooling applications where Nu enhances by ∼47% at 200 W heat input. No work had been reported so far on the investigation of heat transfer characteristics and the entropy generation rate of carbon-based hybrid nanofluids in a microchannel heat sink, which shows the potential in the novelty of the current study. The addition of 0.2 vol% hybrid nanomaterials could be optimum for enhancing the effectiveness of microchannel heat sinks by enhancing the heat transfer phenomenon, which was evident from the performance evaluation coefficient and thermal entropy generation rate.