Improving the performance of radiator heat transfer using Al2O3 nanofluids from local bauxite

To obtain an alternative cooling fluid, Al2O3 nanoparticles were synthesized from local bauxite. Al(OH)3 precursors were extracted from bauxite using the Bayer method. Al2O3 nanoparticles were obtained by calcining the Al(OH)3 precursors at 1200°C for 3 hours. These Al2O3 nanoparticles were analyzed using XRD and surface area meter. Nanofluid was prepared from these Al2O3 nanoparticles with nanoparticle concentrations of 1g / L, 3g / L, and 5g / L. The stability of the nanofluid was evaluated with the help of a zeta potential measuring device. The characteristic of the nanofluid heat transfer was tested using a radiator. According to XRD analysis, it was known that synthesized Al2O3 nanoparticles had alpha and theta phases. The specific surface area of nanoparticles was 30 m2/g with Al2O3 particle size of 50.5 nm obtained from this surface area. The nanofluids were relatively stable with zeta potential of -45 mV, -45.8mV, and -45.4 mV for Al2O3 concentrations of 1g / L, 3g / L, and 5g / L, respectively. The nanofluids created had a heat transfer coefficient greater than water. The increase of heat transfer coefficients were 34%, 37% and 38% for each concentrations of the nanofluids.