Experimental Investigation on Physical and Thermal Properties of Graphite Nanofluids.

Nanofluids can be considered to be the next-generation heat transfer fluids as they offer exciting new possibilities to enhance heat transfer performance compared to pure liquids. In this paper preparation of Ethylene Glycol (EG) based graphite nanofluid by two step method using PVP as surfactant is studied. Four different volume concentrations of 0.05%, 0.2%, 0.86% and 2% nanoparticles are suspended in the EG base fluid by ultrasonication for 5 hours. The effect of shear rate from 10-100s-1 on viscosity of nanofluid is performed at a fixed temperature. The nanoparticle size considered for analysis of viscosity is <50nm. Further, the thermal conductivity of prepared nanofluid is estimated at a constant temperature for nanoparticle size of <50nm and <100nm. From this complete investigation it is concluded that the viscosity of nanofluid increased with change in volume concentration. Thermal conductivity ratio has shown a linear improvement with increasing volume concentration of nanoparticle. Particle size shows an influence on thermal conductivity variation along with volume concentration. [ABSTRACT FROM AUTHOR]