Modeling of Isothermal Bubbly Flow in Vertical Pipes

Turbulent bubbly air/water two-phase flows in a circular pipe were investigated. The phase distribution of air-water bubbly flow in a 57.15 mm i.d., 3.06 m length vertical pipe has been modeled using the 3-D Eulerian-Eulerian multiphase flow approach combined with Population Balance Modeling(PBM). Important flow quantities such as local void fraction, liquid velocity and the normal turbulent stresses were calculated and compared against experimental data of Wang et. al.,(Int. J. Multiphase flow, 13, 3, 327-343, 1987). Good agreement with the experimental data was obtained. It was found that the void fraction profile showed a distinct peak near the wall that means bubbles tended to migrate toward the wall. It was also shown that the observed wall peaking and coring phenomena, and thus the radial void distribution, can be predicted with this CFD-PBM modeling.