Evaluation of source and sink models in the one-group interfacial area transport equation of small pipes for simulating upward bubbly flow with one-dimensional two-fluid model-based code

The interfacial area transport equation (IATE) is able to improve the computation of the interfacial closure model in a one-dimensional two-fluid model (1D-TFM), so it is essential to pay attention to the accuracy and generality of source and sink models in IATE. To evaluate the accuracy and generality of applying the source and sink models in one-group IATE for small diameter pipes to simulate different undeveloped bubbly flows in both small and large diameter pipes, the code where the 1D-TFM is coupled with one-group IATE was developed first, i.e., Solver-IATE. Then, Solver-IATE was used to simulate the coalescence-dominant experiment, the breakup-dominant experiment and the coalescence-breakup-dominant experiment in different diameter pipes with the different models. The results showed that the Hibiki and Ishii (2000) model, Hibiki and Ishii (2002) model, and Dave (2016) model are more suitable for simulating the breakup-dominant experiment, and the Ishii et al. (2001) model is the most accurate model for the coalescence-dominant experiment. Meanwhile, the model can be generally suitable for pipes with different diameters, only when it has the following two characteristics: ① considering wake entrainment and ② considering the turbulence enhancement due to the free movement of bubbles.