Thermal and Rheological Properties of Metallic Oxides Based Nanorefrigerants: Effect of Nanoparticles Type and Shape

Abstract

The thermal and rheological properties of nano refrigerants using different metallic oxides nanoparticles were discussed in this study. Different parameters were considered such as different metallic oxides nanoparticles (Al2O3, CuO, SiO2 and ZnO), a various volume fraction of 1-5%, different temperature preparation of 300-350 K, and different nanoparticle shapes of (spherical, cylindrical, plates, bricks and blades). The thermal conductivity of metallic oxides/R-134a based nano refrigerants was increased by increasing the temperature and volume fraction while decreased by increasing the size of nanoparticles. Furthermore, the data of viscosity ratios suggested a significance increment when the concentration was increased. Therefore, the perfect volume fraction of metallic nanoparticle was considered a significant research parameter to improve the performance of thermal mechanisms. To conclude, the thermal and rheological characteristics were influenced by the shape of solid particles.