The viscosity distribution around a rising bubble in shear-thinning non-newtonian fluids

Abstract

-The viscosity distribution of the liquid around a rising bubble in carboxymethyl cellulose (CMC) aqueous solutions was measured experimentally by particle image velocimetry (PIV). The effect of the concentration of CMC solutions on the viscosity distribution around a bubble and the coupling relations between the viscosity field, flow field and shear stress field were also studied. Results indicated that the specific viscosity (non-dimensionalized by 0 η ) decreases with the increase in CMC solution concentration due to a shear thinning effect. Within the experimental range, similar viscosity distributions of liquids around a rising bubble were found: a hollow cylindrical low viscosity region around the bubble wake and a high viscosity region in the central bubble wake.

Differences in Viscoelasticity of Ophthalmic Polymer Solution after Sterilization

“…However, pseudoplastic behaviors were found in all polymer solutions. The same results were found in previous reports [12][13][14]. The addition of carboxymethylcellulose (CMC), sodium salt, gum arabic, and guar gum to the formulation exhibited pseudoplastic solution behavior.…”

Fiber and film developments from immiscible blends of cellulose acetate propionate and poly(butylene terephthalate)

“…It is generally known that the immiscibility in blends can result in a lower viscosity than those of their individual components because of weak interactions or a lack of interactions between the two components. Generally, a low apparent viscosity is desirable during polymer processing because less energy is required to process the polymer . Therefore, it was important to control the spinning parameters carefully in this study.…”

“…Generally, a low apparent viscosity is desirable during polymer processing because less energy is required to process the polymer. 28,29 Therefore, it was important to control the spinning parameters carefully in this study.…”

Dynamics of a Taylor bubble in steady and pulsatile co-current flow of Newtonian and shear-thinning liquids in a vertical tube

“…However, the understanding of bubble dynamics in non-Newtonian liquids (generally shear thinning or viscoelastic rheology) is important in several industrial applications including food processing (aeration of molten chocolate), de-aeration of paints, oil exploration and drilling applications, and biological systems such as blood embolism (Johnson and White, 1993). Despite the relevance to industrial, natural and biological processes, the literature on the dynamics of Taylor bubbles in non-Newtonian liquids is very limited, and much of the literature on the bubble dynamics that is available deals with nearly-spherical bubbles (Herrera-Velarde et al, 2003;Hassager, 1979;Margaritis et al, 1999;Li et al, 2012;Amirnia et al, 2013;Funfschilling and Li, 2001). Sousa et al (2005) carried out experiments using PIV and shadowgraphy to determine the flow field and velocity of Taylor bubbles rising in stagnant non-Newtonian solutions of Carboxymethylcellulose (CMC) in water, which predominantly had a shear-thinning rheology for the concentrations they considered.…”