Effects of SiO2 nanoparticles addition on performance of commercial engine coolant: Experimental investigation and empirical correlation

Abstract

Thermal conductivity is a key parameter to describe the heat transfer performance of a coolant. In the present study, the thermal conductivity of commercial engine coolant based SiO2 nanofluids was measured using a novel sonic velocity measurement technique and analyzed. SiO2 nanoparticles were dispersed in engine coolant to prepare nanofluids at five different mass concentrations of 0.01%, 0.05%, 0.10%, 0.50% and 1%. The stability of the nanofluids was studied by sedimentation study, light absorbance, and zeta potential analysis. The thermal conductivity of nanofluids was measured from the velocity of sound in those test samples. The SiO2 nanofluid samples showed good dispersion stability. The thermal conductivity of nanocoolant was increased with increasing concentration as well as temperature. However, the result reveals that increasing temperature was more effective than the increase in the concentration of nanofluids. Nanocoolant with 1% concentration at 65 °C showed a maximum enhancement in thermal conductivity value of 21.083%. Finally, a new mathematical correlation was developed in the present study to predict the thermal conductivity of engine coolant based SiO2 nanofluids with high accuracy. The experimental outcome reveals that the thermal performance of commercial engine coolant could be increased with the addition of SiO2 nanoparticles.