Physical 3D models were established for corrugated packing used in the enrichment of the isotope 13C. Computational fluid dynamics (CFD) simulation results indicated that common corrugated packing was not well wetted when used for isotope distillation. It is concluded that liquid misdistribution in the packed tower results from the structure of the packing rather than from the height of the packing beds. The existence of entrainment was also demonstrated by CFD simulation. It is proved that mass transfer equations based on the Nusselt theory are not suitable for distillation calculation in such a corrugated packing system. By comparison, the recently developed structured packing model with a corrugation geometry based on the right-angled triangle, known as Zigzag-pak, describes vapor-liquid distribution properties well and has significant advantages over common corrugated packing due to its better liquid distribution character.