Besides pores and solid material, the input structures used for AddiDict can contain porous domains, i.e., parts of the structure that are not fully resolved in the used discretization. Porous domains are characterized by their flow resistivity. (Navier-)Stokes-Brinkman equations describe the flow in the porous domain. In the pores, the flow is described by the (Navier-)Stokes equations (resistivity (K-1) is zero). The flow field is computed by solving the (Navier-)Stokes or (Navier-)Stokes-Brinkman equations numerically. To use the (Navier-)Stokes-Brinkman equations in AddiDict, additional information about the permeability of the porous media has to be provided. Therefore, a permeability has to be assigned to each material.

More information on the flow solvers and the used partial differential equations can be found in the FlowDict user guide.