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Exhaust gases of diesel vehicles are considered as a major reason of city air pollutions. The DOC(Diesel Oxidation Catalyst) and DPF(Diesel Particulate Filter) have been used to reduce the emissions of diesel vehicles. The DOC can oxides HC, CO and SOF(Soluble Organic Fraction) in the PM emissions, and the DPFs can filter the most of solid PM, such as carbon particles. As the DPFs, wall flow type ceramic honeycomb filters have been commonly used and now being still advanced. However, the cost and durability of the currently used DPFs are not perfect yet. Metal foam is the one of promising materials for the DPFs due to its cost effectiveness, good thermal conductivity and high mechanical strength. The metal foam can be produced with various pore sizes and strut thickness and finally can be coated with catalytic wash-coats with low cost.

Filtration studies about the metal foam filters combined with electrostatic precipitation, which can be used as a new DPF device, have been performed. Filtration efficiency of the metal foam filter is significantly low because most particles are penetrated through the large filter-pores. However the efficiency was considerably improved by forming a high electric field on the filter surface. The pressure drop was not significantly increased by the particle deposition because the particles do not completely clog the filter pores.

In order to improve the predicting capability of KIVA-3V code for a diesel engine, various numerical models were reviewed. From the comparison of TAB, wave and χ - square distribution models for atomization of a liquid fuel jet, it was found that the wave model was most suitable for predicting a diesel spray because of proper breakup length. The high pressure evaporation model, which considered the air in a combustion chamber as a real gas, predicted earlier ignition about 0.7 °CA than the low pressure model. For the diesel ignition, the Hardenberg model predicted shorter ignition delay than the Shell model and measurements, and the Hardenberg model showed the spatially uniform ignition. For soot emission, the phenomenological models suggested by Foster, Belardini and Hiroyasu were studied. The Hiroyasu model could be used effectively for the prediction of soot emission although it did not provide detailed information on soot formation.