An experimental investigation to study the performance characteristics of heat pipe using aqueous hybrid nanofluids

The steady-state performance characteristics of a mesh-wick heat pipe were investigated experimentally across a heat load range of 25W-100W incorporating DI water, Al2O3 nanofluids, and Al2O3+GO hybrid nanofluids respectively. All the nano-suspensions were prepared following the two-step preparation method. Out of all the prepared Al2O3 nanofluids, 1.0 vol.% Al2O3 nanofluid exhibited the highest reduction in adiabatic vapor temperature. The hybrid combination of 75% Al2O3 +25% GO nanofluid in the heat pipe resulted in a maximum decrement of about 21.4%, and 59.5% in the average evaporator temperature, and thermal resistance respectively while offering maximum thermal efficiency enhancement of about 31.4% relative to the base fluid. The 75% Al2O3+25% GO hybrid nanofluid in the heat pipe offered the least thermal resistance at a gravity-assisted inclination of 60o. The current study contemplates the most favourable hybrid combination of Al2O3 and GO nanoparticles for its incorporation in the heat pipe and tries to identify the underlying reasons behind the performance characteristics achieved using hybrid nanofluids and finally projects the future research scope.