RAMPANT is a computer simulation tool developed to model three-dimensional, viscous, turbulent flows through complex geometries. The code is used to analyze the flow through a multiple passage exhaust system, which includes a catalytic converter. The catalytic converter is modeled as a porous flow region that straightens and obstructs the flow. The effect of flow non-uniformity on catalytic converter performance is examined. The applicability of the software to a range of engine system and external flow modeling problems is shown.
