Effect of carrier concentration on rheological behavior of high density PCM slurry

• Experimental study on rheological characteristics of erythritol slurry was conducted. • Effect of density difference on rheological behavior of the slurry were examined. • A particle Reynolds number was introduced to assess non-Newtonian behavior. • A correlation of n’ was developed using solid fraction and particle Reynolds number. Erythritol slurry has demonstrated significant potential as a heat transfer medium. This study focused on the changes in the density difference between dispersed particles and the carrier fluid by varying the carrier fluid concentration within the range of 45–65 mass%. To estimate the density difference, the density of the carrier fluid, an erythritol aqueous solution, was measured at various temperatures and concentrations using a hydrometer. The pressure drop of erythritol slurry was measured in horizontal homogeneous flow. The results indicate that the non-Newtonian characteristics become more pronounced as the carrier concentration decreases, particularly under high solid fraction conditions. Moreover, the particle Reynolds number was proposed as a key parameter for evaluating the non-Newtonian characteristics of erythritol slurry. A correlation was developed between the power-law index n′ , solid fraction, and particle Reynolds number. The calculated values showed good agreement with the experimental values of n’ , with nearly all values within ± 10 % for solid fractions of 0–14 vol% and particle Reynolds numbers of 0.8–2.0.