Hydrodynamic characteristics of free rise of light solid particles and gas bubbles in non-Newtonian liquids

• Published in: Chemical engineering science 1999, Vol.54 (21), p.4825-4830
• Main Authors: Dewsbury, K., Karamanev, D., Margaritis, A.
• Format: Article
• Language: English
• Subjects: Bubbles; Drag coefficient; Exact sciences and technology; Fluid dynamics; Fundamental areas of phenomenology (including applications); Light rising particles; Multiphase and particle-laden flows; Non-newtonian fluid flows; Non-Newtonian liquids; Nonhomogeneous flows; Physics; Terminal velocity
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/S0009-2509(99)00200-6

The main objective of this study was to determine the primary parameters affecting the rise of gas bubbles and light solid particles in non-Newtonian (pseudoplastic) liquids. The results obtained for the rise of light solid particles were used to explain the behavior of rising gas bubbles. These results were also compared to that of free-falling heavy particles. The main parameters studied were the drag coefficient, trajectory of rise, and terminal velocity as a function of the shape and volume of gas bubbles and solid particles, and the rheological properties of the non-Newtonian (pseudoplastic) liquid. It was determined that the most effective method for doing this was with a movable video camera unit. It was discovered that freely rising light solid particles have similar behavior to gas bubbles for a wide range of Reynolds numbers. This indicated that the hydrodynamics of freely rising light particles could be used to describe the behavior of gas bubbles. The comparison of the behavior of light solid particles and gas bubbles allowed us to determine the effect of the internal circulation of a gas bubble on the hydrodynamics of its rise. A new correlation was proposed to predict the drag coefficient and terminal velocity of gas bubbles in non-Newtonian (pseudoplastic) solutions.