Optimising exhaust gas treatment systems
Diesel-powered automobiles offer a number of advantages over their gasoline-powered counterparts, namely better fuel economy, power and durability. In terms of environmental impact, diesel engines produce less carbon monoxide and carbon dioxide, but do however emit more harmful particulate matter. To control particulate emissions, automobile manufacturers install special filters made from ceramic foam that remove particles from the exhaust gas before it is released to the atmosphere. In order to optimise the use of these filters, the industry identified the need for an accurate simulation tool. The Christian-Doppler-Laboratory for Applied Computational Thermofluiddynamics (CDL-ACT) in Austria satisfied this need by creating DexaSIM. The heart of DexaSIM is the Lattice-Boltzmann-Method (LBM) based solver and the Open Source Computational Fluid Dynamics (CFD) flow solver OpenFoam. These two components work in conjunction to model the flow regime for the entire exhaust gas after treatment system. It is not necessary to be a CFD expert to use the software and navigation is aided by the inclusion of a Graphical User Interface (GUI). Users can test the effectiveness of different filter materials and structures. Additional modules address aspects such as soot deposition, filter regeneration and even acoustics since noise pollution is also a concern. CDL-ACT validated DexaSIM with actual measurement data provided from partners in the STYFF-DEXA project. Initial trials of the beta version of DexaSIM have been successful. Negotiations are underway with an organisation active in the automotive software sector for the marketing and sales of DexaSIM. DexaSIM is currently suitable for light-duty diesel vehicles, but could also be adapted to heavy-duty diesel as well as gasoline-powered vehicles. Finally, DexaSIM could possibly be used to model the use of filters to reduce emissions from gas-powered power plants.
