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THE FORMATION BEHAVIOR OF A SINGLE BUBBLE IN POWER-LAW FLUIDS

Abstract

The formation behavior of a single bubble in power-law fluids (carboxymethyl cellulose solution, CMC) and Newtonian fluids (glycerol solution) was experimentally investigated via a high-speed camera. The effects of liquid property, orifice diameter and gas flow rate on bubble volume and aspect ratio were observed. It was found that the formation time and detaching volume increased with the increase of fluid viscosity. The increase of bubble aspect ratio during the bubble formation process was complex, with main emphasis on the decrease in the initial stage and an increase in the final stage along with the shear thinning property variation. Nevertheless, the bubble detaching volume, instantaneous volume and formation time increased following the increase of orifice diameter and gas flow rate. On the contrary, the bubble aspect ratio decreased with the orifice diameter increase but increased with a higher gas flow rate.

Keywords:
Bubble formation; Power-law fluids; Rheological property; Bubble volume; Aspect ratio

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