To accelerate the design of separation columns, packing vendors seek a reliable model of the flow in the complex geometry of separation-column packing. We provide a computational-fluid-dynamics model for the gas flow through various types of structured packing consisting of corrugated sheets. The model is validated on experimental data measured on commercial structured packings Mellapak 250.X, 250.Y, 350.Y, and 500.Y. Furthermore, the measurements on Mellapak 250.X and 250.Y were performed with three different gases, He, N-2, and SF6, to cover the widest possible range of operating conditions. A successfully validated model was used to estimate the dry-pressure loss in relation to the gas flow and selected geometric parameters of the packing. The modified geometric parameters were, specifically, (i) the slope of the packing channels to the horizontal plane, (ii) the specific area of the packing, and (iii) the packing-perforation density.