Characterization and modelling of density, thermal conductivity, and viscosity of TiN-W/EG nanofluids

Thermal conductivity, dynamic viscosity, and density of TiN nanofluids (NFs) with different base mediums have been characterized for the prospect of developing new thermophysical property correlations in this work. Characterizations of morphology and crystal structure of nanopowder were made using scanning electron microspore and X-ray diffractometer. Set of NFs was prepared in a base liquid mixture of water-ethylene glycol W/EG 60:40 and 40:60 by an ultrasound-assisted two-step method. Meter Group KD 2 Pro analyzer operated on transient line heat source method was used for the thermal conductivity test. The viscosity and density of NFs were measured with Anton Paar rotational rheometer MCR 302 and oscillating densimeter DMA 4500M. All experiments were implemented for volume fractions of NF between 0.25 and 1.0 vol% in the temperatures range of 293.15-333.15 K. The findings indicate that density and viscosity decrease with increasing temperature, whereas the thermal conductivity of nanofluids is enhanced depending on NP concentration. The W/EG 60:40 base mixture exhibited higher thermal conductivity enhancement and 40:60 base mixture had greater viscosity growth among all analyzed NFs. Moreover, the difference in base fluid fractions does not lead to a significant variance in the density ratios of NFs. Empirical correlations developed for examined properties with effects of particle concentration, temperature, and base liquid ratio are capable of accurately reproducing the properties data within 15% deviation. Graphic abstract