Thermal and electrical conductivity of silicon carbide nanofluids

Abstract

Nanofluids are promising heat transfer fluids, which possess superior heat transfer properties compared with those of conventional fluids such as water, ethylene glycol, and engine oil. Nanofluids at volume concentrations of 0.5–5% were prepared by dispersing nanoparticles of silicon carbide (SiC) in ethylene glycol (EG) and distilled water (DW) using a two-step method. The stability of nanofluids was evaluated via zeta potential and also by analyzing the spectra obtained with a UV-vis spectrophotometer. The thermal and electrical conductivities of SiC/EG and SiC/DW nanofluids were determined. The results show that the SiC/DW possess better stability than SiC/EG nanofluids. Maximum thermal conductivity increases of 25% and 16% were observed for the SiC/EG and SiC/DW nanofluids at 5% volume concentration, respectively. In addition, it was observed that both nanofluids exhibited an increase in electrical conductivity with increase in the volume concentration of SiC nanoparticles. Specifically, an approximately 58 and 148 times increase in electrical conductivity, relative to the base fluid, was attained for the SiC/EG and SiC/DW nanofluids at 5% volume concentration, respectively.