Application of two population balance models to predicting large scale multi-size bubbly flow

Aiming at investigating fluid flowing behaviours in large scale multi-size bubbly flow, two population balance models, named Bubble Number Density Transfer (BNDT) model and Multi-Size-Group (MUSIG) model coupled with bubble coalescence and breakage mechanism respectively, are employed to simulate the MTLOOP (Multi-phase Loop) experiment with characteristics of coalescence dominating trends. In comparison to experimental data, both models are able to well capture the dynamic evolution trends of bubble diameter and transition of gas volume fraction distribution, but the computing period of BNDT gets shorter by 1/10~1/20 than that of MUSIG under the similar predictions, thus BNDT model is more appropriate for predicting large scale multi-size bubbly flow in rocket engineering