In  Flow Simulation Project in Solidworks we consider flow in a section of an automobile exhaust pipe, whose exhaust flow is resisted by two porous bodies serving as catalysts for transforming harmful carbon monoxide into carbon dioxide.

Open the SolidWorks Model
1 Click File, Open.
2 In the Open dialog box, browse to theCatalyst.SLDASM assembly located inthe First Steps - Porous Media folderand click Open (or double-click theassembly). Alternatively, you can dragand drop the Catalyst.SLDASM file to an empty area of SolidWorks window.

When designing an automobile catalytic converter, the engineer faces a compromise between minimizing the catalyst's resistance to the exhaust flow while maximizing the catalyst's internal surface area and duration that the exhaust gases are in contact with that surface area. Therefore, a more uniform distribution of the exhaust mass flow rate over the catalyst's cross sections favors its serviceability

. The porous media capabilities of Flow Simulation are used to simulate each catalyst, which allows you to model the volume that the catalyst occupies as a distributed resistance instead of discretely modeling all of the individual passages within the catalyst, which would be impractical or even impossible.

Here, as a Flow Simulation tutorial example we consider the influence of the catalysts' porous medium permeability type (isotropic and unidirectional media of the same resistance to flow) on the exhaust mass flow rate distribution over the catalysts' cross sections. We will observe the latter through the behavior of the exhaust gas flow trajectories distributed uniformly over the model's inlet and passing through the porous catalysts. Additionally, by coloring the flow trajectories by the flow velocity the exhaust gas residence time in the porous catalysts can be estimated, which is also important from the catalyst effectiveness viewpoint.