Characterization of Thermophysical and Electrical Properties of SiC and BN Nanofluids

Experimental data associated with the thermophysical properties (TPPs) of various nanofluids (NFs) are essential for their diverse applications in energy storage and conversion, as well as thermal management. This study experimentally investigated important TPPs such as thermal conductivity (TC), thermal diffusivity, density and viscosity, as well as the electrical conductivity of two new types of NFs, namely silica (SiC) and boron nitride (BN) nanofluids. The NFs are prepared at five low concentrations of nanoparticles from 0.01 to 0.05 vol.% dispersed into a mixture of ethylene glycol (EG) and distilled water (DW). The TPPs are measured, and their enhancements are evaluated in comparison with their base fluids. The results show a good increase in TC and thermal diffusivity for both types of nanofluids with increasing concentrations until reaching the maximum enhancement of about 4.4% for the SiC nanofluid and about 7.0% for the BN nanofluid at the same concentration (0.05 vol.%). On other hand, a Newtonian rheological behaviour is observed, and viscosity and density are also found to increase for both types of NFs, where the maximum increase in viscosity and density at 0.05 vol.% are found to be 5.2% and 0.3%, respectively. The electrical conductivity also increases by up to 3.2 times for SiC nanofluids and 2.8 times for BN nanofluids at the maximum concentration of these nanoparticles (0.05 vol.%) compared with the base fluid (EG/DW). The overall evaluation of the obtained results demonstrates the great potential of these nanofluids in heat transfer applications.