Bubble column reactors are widely employed in various applications. Nowadays computational fluiddynamics (CFD) provides the state-of-the-art capabilities of simulating the hydrodynamics in these reactors. In the present work, bubble column is numerically simulated by using open source CFD tool, OpenFOAM 2.3.1. Euler-Euler two-fluid model is used for the simulations. In the first part, OpenFOAM simulations are validated with experimental data from the literature over a column diameter range of 138–600 mm and the superficial gas velocity in the range of 19–169 mm/s. The velocity and holdup patterns as well as circulation patterns in the bubble column are compared. In addition, Fluent simulations are performed for the same conditions in order to compare the accuracy of OpenFOAM solvers. In the second part of the work, the validated OpenFOAM solver is applied to simulate the flow field in the 120 mm ID bubble column with and without internals. The internals consisted of (a) one vertical central rod of 36 mm diameter, (b) one central rod of (a) and four vertical additional rods of 12 mm diameter, (c) one central rod of (a) and fourteen vertical additional rods of 12 mm diameter. The OpenFOAM simulations are found to be in good agreement with the experimental data for both bubble columns with and without internals. As regards to experiments, radial profiles of gas hold-up and the liquid velocity were measured by using the radioactive particle technique (RPT). Such measurements were made at four axial locations.