Various chemical products are synthesized in processes using gas/liquid reactors with bubbly flows. Hence, there is a significant interest in a more efficient process design as well as in process intensification with a strong focus on this reactor class. However, the design of industrial gas/liquid reactors requires more detailed information about the flow structures and characteristics of two- or multiphase systems. The basic models for two-fluid model simulations of dispersed gas/liquid flows in bubble columns at high gas fractions are presented.