In this paper, a steady three-dimensional two-fluid computational fluid dynamics predictive model is presented to simulate the dispersed bubbly flow split phenomenon in a T-junction with 50mm diameter for all arms. The fluid is treated as a mixture and the fundamental mass, momentum and turbulent equations are solved to account for the flow parameters, where the turbulence is modeled by the standard $k-{varepsilon}$ model. Simulation results imply that the gas phase inclines to flow into the side arm even for small extraction rate conditions, because the pressure difference of the side arm to inlet is much larger than that of run arm to inlet. The analysis of velocity field reveals that it is the inertia difference between the two phases that leads to the phase split phenomenon. The effect of bubble diameter on flow split is also investigated and it is found that split efficiency is greatly influenced by it. The computed solutions are compared with experimental data and a good agreement is achieved.