Microgravity gas–liquid flow through packed beds

Analysis of possible physical mechanism involved in the process of transition of bubble-to-pulse flow regime in cocurrent gas–liquid flow through a packed bed in microgravity demonstrates that the transition can be described by the key dimensionless group Suratman number and the ratio of gas to liquid Reynolds numbers. This result establishes a physical basis to the existing empirical transition equation which is also based on the same dimensionless groups. Furthermore, the concepts of driving-to-resistance force ratio and pore-level bubble flow mechanism have been utilized to explore the basis of the existing modified friction factor correlation for two-phase flow through a packed bed under microgravity.