Effects of Contraction Ratio on Elastic Instability of Hyaluronate Solution in a Micro Channel

Flow behaviors of sodium hyaluronate (HA-Na) in water solution and in phosphate buffered saline (PBS) solution as a viscoelastic fluids in planer abrupt contraction-expansion channels has been observed in this study. Especially, the effect of the geometry of the flow path on the flow behavior was focused on. The corner vortices in the corner of the upper region in the abrupt contraction-expansion channels were also analyzed to quantify the flow characteristics. The elasticity numbers of the solution, which is affected by rheological properties of the solution and the channel geometry had a big influence on the fluidity, that is, stable or unstable, when the concentration of the solution in lower. It was concluded that such stable and unstable flows are categorized on Wissenberg-Reynolds number space.