Mesoregime-Oriented Investigation of Flow Regime Transition in Bubble Columns

Abstract

This work investigates regime transition in bubble columns through a mesoscale framework. The dominant mechanisms in bubble columns are analyzed according to the concept of mesoregime. Model predictions with the modified stability condition agree well with experimental data. It indicates a scenario of the regime transition. That is, the homogeneous regime is liquid dominated, which is characterized by the dominance of liquid over the movement of small bubbles, while the heterogeneous regime is gas-dominated, which is characterized by the dominance of large bubbles over the liquid movement. Consequently, the transition regime is a mesoregime depending on the principle of compromise in competition. The holdup profiles of the three regimes form an enclosed structure, which is corroborated by experiments in the literature. Moreover, the influence of superficial liquid velocities on the regime transition can be qualitatively captured by the model. Also, a GPU solver is developed to cope with the traversal optimizing procedure.