Measurements of the viscosity of suspensions (nanofluids) containing nanosized Al2O3 particles
Huaqing Xie, Lifei Chen and Qingren Wu
Alumina nanoparticle suspensions (nanofluids) were prepared and their viscosities were measured. The effects of the volume fraction of the solid phase, the base fluid, the agglomeration of the nanoparticles, and pH value on the viscosity have been investigated. The experimental results show that the addition of the nanoparticles into the base fluid leads to the increase of the viscosity and the enhancement ratios increase with the volume fraction of the solid phase. The viscosity of the nanoparticle suspension is much larger than the corresponding value predicted by the theoretical formula. The enhancements ratio of the viscosity of ethylene glycol (EG) based suspensions are smaller than those of water based suspensions, indicating the significant influence of the base fluid on the viscosity of the fluid-nanoparticle mixtures. The agglomeration in nanoparticles makes the suspension have larger viscosity.