CFD Models (Turbulent Models and Interfacial Forces) Incorporated with the Population Balance Model (PBM) Have Been Validated, Azimuthally, with the Gamma-Ray-Computed Tomography (CT) Results to Address the Effect of the Presence of Internals with Different Arrangements and Diameters. the Superficial Gas Velocity Applied Was Varied from 0.05 to 0.45 M/s. the Results Exhibit the Capability to Predict the Hydrodynamics of the Bubble Column, Further Incorporating the Population Balance Model and Promoting the Prediction of Simulation in High Superficial Gas Velocity. the Effect of Internals Revealed that the Gas Holdup Was Significantly Enhanced in the Bubble Column's Wall Region, While the Gas Holdup Was Increased Remarkably in the Center and the Wall Regions of the Bubble Column Equipped by Internals of 1 In. Diameter More Than in Internals of 0.5 In. However, Internals with a Hexagonal Arrangement Increase the Gas Holdup in the Central Region and Less in the Wall Than in the Circular Arrangement.