Cooling Characteristics of Water Based Nanofluids With Agitation

Abstract

Abstract A series of quenching experiments was performed according to the ISO 9950, ASTM 6200-01, and ASTM D6482-06 standards. Water based nanofluids with 0.01, 0.1, and 0.2 g/L TiO2 were prepared using a two-step method and ultrasonic homogenization. The nanofluids were tested to see the possibility of their application as high temperature heat transfer fluids. Nanoparticles used in this series of experiments were 50 nm in diameter. All of the cooling curves were recorded and analyzed using the ivf SmartQuench system. The first set of experiments was conducted under still conditions according to the ISO 9950 standard. Pure water and nanofluids were investigated. The addition of nanoparticles showed an effect on the full film phase duration, an increase in the maximum cooling rate, and a change in transition temperature. A second series of quenching experiments was conducted according to ASTM D 6482-06. For this purpose, a quenching bath with agitation was built at the QRC. Three levels of agitation were tested: one according to the standard, 1000 rpm, one below, and one above the specified speed. Experiments with pure water and all three nanofluids were conducted and cooling curves recorded. The cooling curves were analyzed using software ivf SQintegra ver4.0. The effects of agitation and nanoparticles contents on cooling characteristics were compared.