Gas-liquid flow dynamics in pipes is a complex phenomenon encountered in many industrial spheres. Particularly, in petroleum production and transportation the design of the facilities, safety, and efficiency of the industrial operations strongly depend on accurate prediction of flow behavior. Since the seventies, two-phase flow models and correlations predicting the liquid holdup and pressure drop, have been actively developed. However, there are still mismatches between model predictions and experimental results. These discrepancies may be attributed to the benchtop limitations in length, complexity of the gas-liquid interface, and accuracy of empirical correlations used within a model.