Rheology of Ice Slurry in Circular Pipe at Different Freezing-Point Depressants

The utilization of ice slurry as a pumpable phase-change material has been getting a lot of attention in research and development discourses. This study attempted to investigate the rheological characteristics of ice slurry at different freezing-point depressants through experiments. Ice slurry was formed by mixing water and different freezing-point depressants (monoethylene glycol, ethanol, and sodium chloride) at a 20% initial concentration. Rheology tests were conducted on the transition from laminar to turbulent flows in a circular pipe. The inner dimension of the pipe was 12.7mm in diameter, while the ice mass fraction varied in between 0-28% depending on storage time of ice slurry. Experimental results showed sodium chloride ice slurry to have a higher pressure drop and friction factor compared to those of monoethylene glycol and ethanol ice slurry ones at the same initial concentration and ice mass fraction level. In general, ice slurry was discovered to behave as a Newtonian fluid at 10-15% ice mass fractions, as a shear thinning fluid at 15-20% ice mass fractions, and a shear thickening fluid at 20-28% ice mass fractions. Later, experimental data of shear stress were compared to Ostwald-deWaele and Herschel-Bulkley models based on Mellari method. In fact, a modified Herschel-Bulkley model for monoethylene glycol ice slurry showed a close agreement with experimental data with 4.7% mean deviation. In addition, the experimental viscosity data were compared to the Einstein, Jeffrey, Kunitz, Guth, Steimour, Vand, Mooney, Simha, Happel, Ford, Thomas dan Morio-Ototake models. The best fit was only produced with Morio model for values at low ice mass fraction (Xis<15%).