For fast flows the first FlowDict GeoApp might not converge. In this case, the Air Permeability Test (Forchheimer) can be very useful.

The macro runs two air permeability computations with low pressure drops, using LIR or SimpleFFT. From the results, a Forchheimer Approximation is done for the defined pressure drop.

After clicking Edit, the result file name, the pressure drop for the prediction, the solver, and the pressure drop for the two simulations can be changed.

For the two simulations the permeability in Z-direction is computed using Navier-Stokes(-Brinkman) with either the LIR or SimpleFFT solver. This GeoApp creates three result files and two corresponding result folders. The Forchheimer result file keeps the entered Result File Name. For the flow simulations the result file name is automatically expanded by the values for Pressure drop 1 (here, 10 Pa) and Pressure drop 2 (here, 50 Pa), respectively.