This command solves a boundary value problem to determine the stationary flow through the media. If all material IDs present in the 3D structure model describe either fluid or solid materials, the Navier-Stokes equation is solved. If some material IDs represent unresolved porous materials, the Navier-Stokes-Brinkman equation is solved.

In this command, the flow boundary conditions are aligned with a space direction - one side of the domain is the inflow area and the opposite side of the domain is the outflow area. As boundary conditions, you can prescribe flow rate, inflow velocity, or pressure.