In the present work, a computational fluid dynamic (CFD) simulation has been performed to investigate single and two-phase vortex tube. Air in compressed form and partially condensed phase are used as working fluid, respectively. Simulation has been carried out using commercial CFD software package fluent 6.3.26. A detailed study has been performed to generate the profiles of velocity, pressure, and pathlines. These profiles provide an insight on how the process of energy separation as well as the flow field in the vortex tube gets affected on introduction of a liquid phase. The result shows that in case of cryogenic vortex tube, the flow reversal takes place closer to wall due to presence of a very thin wall adhering liquid film, while, in single-phase flow vortex tube, flow reversal is observed at the central portion. The model also predicts that presence of recirculation zone near warm end diminishes the refrigeration effect of vortex tube for two-phase flow.