• MgO, SiO₂, Y₂O₃/water thermal conductivity in mono, binary, and ternary were studied. • Upward trend in thermal conductivity are observed with temperature and concentration. • Mono nanofluid with MgO exhibited the highest enhancement in thermal conductivity. • Ternary nanofluid has good performance, but with lower thermal conductivity than MgO. • A model as function of temperature and concentration with R²>0.99 was developed. This study investigated the thermal conductivity (TC) of mono, binary and ternary hybrid nanofluids (NFs) formulated using Y₂O₃, SiO₂ and MgO nanoparticles dispersed in a water-based fluid. The NFs were synthesized through a sequential two-phase approach, where solid NPs were initially prepared and subsequently dispersed into the aqueous base fluid via ultrasonic agitation. TC measurements were conducted using the transient wire technique under thermal conditions ranging from 20 - 60 °C. Mono nanofluids (MNFs) containing individual nanoparticles (Y₂O₃, SiO₂, or MgO) were tested at solid volume fractions (SVFs) of 0.06%, 0.08% and 0.1%. Binary hybrid nanofluids (HNFs), including combinations of SiO₂–Y₂O₃, Y₂O₃–MgO and SiO₂–MgO, were examined at equal SVFs. Ternary hybrid nanofluids (THNFs), consisting of a mixture of SiO₂, Y₂O₃ and MgO, were also tested at SVFs ranging from 0.06% to 0.1%. Experimental findings confirmed a rise in TC corresponding to the elevation of both temperature and SVF. Among the samples, the MNF containing MgO at 0.1% SVF and 60 °C exhibited the highest TC enhancement 9.8% compared to the base fluid (BF). Finally, an empirical correlation was proposed to estimate the TC of the NFs based on the experimental data.
Soltani et al. (Fri,) studied this question.