Investigation on interphase force modeling for vertical and inclined upward adiabatic bubbly flow

Modeling of interphase forces plays an important role in two-phase bubbly flow simulation. Due to the complexity of two-phase interaction, a substantial number of models have been developed. The applicability and accuracy of these models have been investigated mainly for vertical cases. Study under inclined condition can rarely be found. In the present study the characteristics of different models for interphase forces, including drag force, lift force, wall lubrication force and turbulent dispersion force, are investigated. The effects of interphase forces on the phase distribution for vertical and inclined bubbly flow are evaluated by modeling of DEDALE (Grossetete, 1995) and Xing et al. (2013) experiments. It is found that interphase forces have some different influences on the phase distribution under vertical and inclined condition. Under vertical condition large lift force can result in the high peak of void fraction, whereas under inclined condition the lift force gives the opposite effect due to the change of liquid phase velocity field. Two sets of optimal model combination are obtained by stepwise screening. For the investigated vertical cases a set of model combination including the Ishii-Zuber drag force model, Saffman-Mei lift force model, Hosokawa wall lubrication force model and FAD turbulent dispersion force model is preferable. For investigated inclined cases a set of model combination including the Simonnet drag force model, Tomiyama lift force model, Hosokawa wall lubrication force model and FAD turbulent dispersion force model is the most suitable.