Synthesis of new dihybrid nanofluid of TiO2/MWCNT in water–ethylene glycol to improve mixture thermal performance: preparation, characterization, and a novel correlation via ANN based on orthogonal distance regression algorithm

Nanofuid refers to the mixture of fuid and solid nanoparticles. If this mixture contains more than one NP or fuid, it is called “hybrid nanofuid”; further, if HN contains more than one NP and also more than one fuid, it is called “dihybrid nanofuid.” In this research, frst, titanium dioxide NP was dispersed in the water–ethylene glycol basefuid and formed an HN. Then, thermal conductivity of HN was measured. After that, MWCNT NP was added to the HN and formed a DHN. Further, TC of DHN measured. Both HN and DHN TCs were compared, and the results revealed that by adding MWCNT, thermal conductivity enhanced about 30.83% (from 25.65% of HN to 56.48% of DHN). On the other hand, to analyze the phase structure, and to observe the microstructure, X-ray difraction analysis, energy-dispersive X-ray analysis, and feld emission scanning electron microscopy were examined. The measured TC for both samples was at volume fractions up to 1.0% and temperatures up to 50 °C. After an experimental study, two novel correlations were calculated by the curve-ftting method for HN and DHN, individually. In the end, to predict the other Vf and temperature, an artifcial neural network has been modeled for both HN and DHN.