Measuring Electro-Thermo-Physical Properties of Mineral and Synthetic Ester Based Dielectric Fluid Dispersed with Silica Nanoparticles

This paper presents measurement results of thermal conductivity, AC breakdown voltage, and viscosity of two types of nanofluids, viz. mineral oil based and synthetic ester based, prepared using silica nanoparticles of size less than 50 nm. The enhancement achieved in thermal conductivity was about 14% at 0.05% (w/v) of silica nanoparticles in synthetic ester while those in mineral oil based nanofluid it was 11%. The results agree well with theoretical estimate by Hamilton and Crosser Model. Although there is no change in AC breakdown voltage at initial concentration of nanoparticles up to 0.02 %( w/v), the value thereafter decreases marginally in both types of nanofluid. This may be mainly due to increase in viscosity at higher nanoparticle concentration level. Overall, it has been found that there has been a maximum and positive influence on the thermal conductivity of the dielectric fluids due to nanoparticle dispersion.