In the Flow Calculation panel on the top left, select the Flow Solver Type to be used for solving the chosen partial differential equations from the pull-down menu (EJ, SimpleFFT, or LIR). EJ cannot be selected for solving Brinkman equations.

It is also possible to choose Load from file to import the result file (*.gdr) of a fluid flow simulation previously executed with FlowDict or AddiDict. In this case, computational time is saved by re-using this result, and no additional flow simulation must be executed.

Checking Analyze Geometry performs an analysis of the geometry before the solver computations.

If no percolation path through the structure is found, the partial differential equation does not need to be solved, and a permeability of 0.0 is directly reported as the solution.

Furthermore, the solver operates on the whole structure, regardless of which parts are connected or unconnected. However, unconnected components are not transport relevant, thus the effort of solving in these parts is not necessary.

For these reasons, a geometrical analysis is routinely run to determine whether a through path exists. After the analysis is finished, unconnected components are removed from the computational grid.

This may speed up the computations but requires some time for the geometrical analysis, especially for very large structures. So if you know beforehand that there are no unrelevant parts or that the structure has been processed to eliminate them, the geometry analysis can be switched off by unchecking Analyze Geometry.