Improving heat transfer performance of an automobile radiator using Cu and Ag doped TiO2 based nanofluids

Abstract In this study, effects of using nanofluids on heat transfer performance in automobile radiators were investigated. Four different types of nanoparticles were prepared to be used in nanofluids; (i) pure Ti O 2 , (ii) Ti O 2 doped with 0.1% Ag , (iii) Ti O 2 doped with 0.3% Ag , (iv) Ti O 2 doped with 0.1% Cu . These nanoparticles added into the base-fluid (50:50 ethylene glycol – water mixture by volume) with ratios of 0.3, 0.5, 1 and 2%. The results of this study were evaluated both experimentally and theoretically. According to the experimental results, a net change was observed in thermal conductivity of 0.3% Ag -doped nanofluids. The highest increase for the nanofluids with concentrations of 1% and 2% was found to be 5.615% and 11.094%, respectively. A theoretical analysis was conducted to find the maximum potential of nanofluids without operational problems. It is safe to say that doping with Ag improves the heat transfer properties of nanoparticles, and this improvement is consistent with the increase in the doping amount. According to the results of the theoretical analysis, the increase in convection heat transfer coefficient was determined to be 26.15% and 27.72% for 0.3% Ag -doped Ti O 2 nanofluids with concentrations of 1% and 2%, respectively.