The thermal conductivity modeling of nanofluids involving modified Cu nanorods by Ag nanoparticles

Single Cu nanorods and decorated Cu nanorods with Ag nanoparticles (Cu-Ag nanorods) are synthesized by hydrothermal procedure for investigation the thermal conductivity of water-based nanofluids. The characterization of the synthesized samples is carried out using XRD and TEM. The XRD results show that the observed characteristic peaks belong to crystalline structure of Cu and Ag. The results of TEM reveal that spherical Ag nanoparticles with attach on the surface of Cu with rod morphology. The thermal conductivity variation of the prepared nanofluids is studied by changing the temperature (ranging from 25°C to 55°C) and weight fraction (ranging from 0.25%wt to 1%wt). The results show that the thermal conductivity enhances by increasing the both of temperature and weight fraction. The collation between the thermal conductivity of Cu nanofluids and Cu-Ag nanofluids verifies that the thermal conductivity of Cu-Ag nanofluids is higher than that of Cu nanofluids. Theoretical models compare the measured values of the thermal conductivity in the both nanofluids. The results show that in both of studied nanofluids, the measured magnitude of thermal conductivity is more than that of estimated amount by theoretical equations.