Experimental investigation of specific heat of aqueous graphene oxide Al2O3 hybrid nanofluid

Abstract

The specific heat of aqueous graphene+Al2O3 (1:1) hybrid nanofluid was measured using the cooling method. The influence of nanoparticle mass fraction and temperature on the specific heat capacity of the hybrid nanofluids was investigated, the specific heat of the hybrid nanofluid was compared with that of aqueous graphene oxide nanofluid and Al2O3 nanofluid. A fitted formula of the specific heat of the hybrid nanofluid was proposed based on the experimental data. It indicates that the specific heat reduction ratio increases with increase of nanoparticle fraction and the maximum reduction ratio is 7% at 0.15 wt.% at 20?C. The mass fraction of nanoparticle affects the specific heat of hybrid nanofluid more significantly at lower temperature. Temperature impacts the specific heat more distinctly than the nanoparticle fraction. The specific heat increases with temperature and the maximum specific heat reduction ratio of the hybrid nanofluid diminishes from 7% at 20?C to 2% at 70?C at the mass fraction of 0.05%.