Experimental studies on thermal and rheological behaviour of TiO2-PAG nanolubricant for refrigeration system

Thermal conductivity and rheological properties of TiO2-PAG nanolubricant for 0.07 to 0.8% volume fractions in the temperature range 20 degrees C to 90 degrees C have been investigated. The nanolubricant is prepared using two step method. The results showed that the thermal conductivity and viscosity of nanolubricant increase with increase in volume fraction and decrease with increase in temperature. The measured thermal conductivity and viscosity are compared with that obtained from classical models and the classical models fail to predict these properties accurately. The highest thermal conductivity and viscosity are observed to be 1.38 and 10 times greater than that of pure lubricant for 0.8% and 0.6% volume fraction respectively. Non-Newtonian shear thinning behaviour of TiO2-PAG nanolubricant was confirmed by computing power law and consistency indices. The optimum value of volume fraction for refrigeration application is 0.4%. (C) 2017 Elsevier Ltd and IIR. All rights reserved.