For the sinter process the productivity is as important as the quality of the sinter and thereby bed or packing permeability is seen as one of the key factors. Numerous prior studies experimentally investigated permeability and pressure drop of sinter raw-mix packings. This thesis offers a new approach to the topic based on numerical methodology by application of the digital material laboratory GeoDict for generation of virtual packings of free formed particles. Therefore, different kinds of methods are explored to generate small representative volumes with realistic granular packing structure. Alternatively in a top-down approach, a CT-scan of product sinter was used as a starting point for the generation of ideal dense packings. Structural parameters of the virtual packings were characterized by a combined set of analytical and numerical methods. In the follow-up step the porous gas flow in the virtual model packings is investigated by numerical flow simulations. Permeability and specific pressure drop are evaluated as characteristic parameters. The numerical results are then compared to experimental data and empirical model equations.