Novel Approach to Augment Thermal Conductivity of Dihybrid Nanofluids

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 degrees 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.