Novel Approach to Augment Thermal Conductivity of Dihybrid Nanofluids

Abstract

In this experimental study, the copper oxide (CuO) nano–particle (NP) was mixed with a water/ethylene glycol hybrid base fluid to form a hybrid nano–fluid (HNF). Further, this HNF was mixed with a MgO nano–particle and also separately with a TiO2 nano–particle to form two different dihybrid nano–fluids (DHNFs). For the preparation of nano–fluids, two-step procedure was used. In all three cases, the volume fraction of the NP was 0.25, 0.5, 0.75, 1.0, and 1.25%. The thermal conductivity (TC) of HNF was measured with KD2 pro and compared with the DHNFs' at temperatures 26, 28, 30, and 32°C. It was inferred that the CuO/TiO2 nano–particle addition in the water/ethylene glycol hybrid base fluid resulted in an average of 0.8% rise in thermal conductivity at chosen temperatures and volume fraction. Also, the agglomeration due to the presence of CuO/MgO was a critical issue at higher volume fractions such as 0.75, 1, and 1.25%. The MgO nano–particle addition in the CuO nano–particle also resulted in a 0.6% increase in thermal conductivity at 0.25 and 0.5% volume fraction. The result was that in the CuO/MgO - water-ethylene glycol nano–fluid combination the TC was enhanced by 29.57% compared with CuO/water/ethylene glycol at a volume fraction increase of 0.5%. Also, it was noted that the nano–particles volume fraction has little effect on thermal conductivity improvement at higher proportion.