Image Identification of Large Bubble Breakup in Slug Flows
B.L. Barboza(1,2), J.B.R. Loureiro(1,2), A.P.S. Freire(1,2)
1: Interdisciplinary Center for Fluid Dynamics (NIDF/UFRJ), Federal University of Rio de Janeiro, R. Moniz Aragão No. 360, Bloco 2, 21941-972, Rio de Janeiro, Brazil
2: Mechanical Engineering Program (PEM/COPPE/UFRJ), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
DOI:
The work resorts to high-speed filming to discuss the effects of large bubble breakup on the properties of gas-liquid slug flow subjected to geometric constraints and high turbulence. Under this condition, image analysis introduces several challenges, including image blurring from violent movement, low contrast in the liquid slug and in the film region, and difficulty in isolating phases (superposed views, bubble coalescence and breakup, and turbulent interfaces). The work discusses the effects of strong local disturbances on the fine and gross properties of the flow. The sizes of large bubbles, their passage frequency and velocity, the size and velocity distribution of small bubbles, and the lengths of the liquid slugs are assessed and discussed with a view on understanding how changes in these parameters have an effect on the pressure drop. The effects of change in the rheology of the liquid phase are also discussed. Newtonian (water) and non-Newtonian (CMC solutions) fluids are tested. The main benefit of high-speed filming is that it allows for the collection of quantitative and qualitative data under circumstances that would otherwise need the use of several measurement methods.
