Virtual diesel particulate filters: Simulation of the structure, exhaust gas flow and particle deposition

Diesel particulate filters are gradually making their way into production to keep emissions of fine dust to a minimum. But which filters are most efficient at extracting the noxious particles? How do the geometrical details of the filter material affect the filter properties? The new simulation software FilterDict could in the future significantly reduce the number of prototypes required, cutting time and cost of development - and offer some powerful new features, as well. It allows simulation of how fast and how far particles penetrate into the filter, for example - using any kind of filter material. As input parameters, FilterDict requires a filter material model from the 3-D microstructure generator GeoDict, various physical parameters, and the particle size distribution. The software computes the path of the soot particles through the filter medium. The simulation shows how much soot is deposited in which part of the filter. Therefore, the design of the filter can b e optimized to achieve long regeneration intervals, low fuel consumption and a high engine rating. The simulation program has already passed its first practical test. In an experiment, researchers examined two diesel particulate filters, and compared the results with those of the simulations.