Thermal, exergetic, and performance analysis of dissimilar-shaped nanoparticles hybrid nanofluid for flow across minichannel heat sink

In the present study, the effect of dissimilar-shaped nanoparticles (i.e., graphene platelet shape, Al2O3 blade shape, MWCNT cylindrical shape, and Fe3O4 brick shape), by 50:50 v/v., hybrid nanofluids in a minichannel heat sink with varying volume flow rate and vol. fraction (0.1–1%) has been discussed. Comparative thermal performance parameters (COP, comparison factor, and figure of merit) and exergetic analysis (inlet, outlet exergy, and exergy loss) have been investigated along with the heat transfer rates. The study is carried out with water as the reference fluid. The dissimilar-shaped hybrid nanofluid exhibits better results in terms of heat transfer coefficient, Nusselt number, inlet and outlet exergy (maximum enhancement of 0.201%, 1.498%, 0.0431%, and 1.192%, respectively, at 0.000004 m3 s−1 volume flow rate, φ = 0.001, an inlet temperature of 25 °C). In terms of performance parameters, water exhibits better results while the combination of dissimilar-shaped hybrid nanofluids renders adverse effects. The cylindrical brick (MWCNT-Fe3O4) blend exhibits the highest thermal performance among different examined coolants, the blade cylindrical (Al2O3-MWCNT) blend exhibits the best exergetic performance, and water exhibits the best comparative performance characteristics like COP, CF, etc.