Diesel particulate filters are gradually making their way into series 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? Until now, researchers and developers have had to conduct a series of tests to answer questions like these: They build prototypes, which then have to prove their abilities in experiments. This involves using a huge number of test filters.
A new simulation software could in future significantly reduce the number of prototypes required, cutting the time and cost of development – and offer some powerful new features, as well. For the first time, the 3-D simulation software FilterDict gives full insight into the filtration process. It allows simulating how fast and how far particles penetrate into the filter, for example – using any kind of filter material. As its input variables, FilterDict requires the filter material model from the microstructure generator GeoDict, various physical parameters, and the particle size distribution. The program calculates the path of the soot particles through the filter media. The simulation shows how much soot is deposited in which part of the filter. Therefore, the design of the filter can be 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 conducted with fellow scientists at Bosch, the researchers examined two diesel particulate filters, and compared the results with those of the simulations. Now, Bosch and ITWM are extending their cooperation to simulate up to a hundred filters. Unsuitable designs can then be excluded from the outset – the researchers only build prototypes of filters that achieve satisfactory results in FilterDict. Only these are tested in the laboratory.