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A light duty truck Renault Trafic with a naturally aspirated 2.5 l diesel engine was equipped with metal particulate filters of different sizes, installed at different positions along the exhaust pipe of the vehicle. The filters were operated on diesel fuel doped with a cerium based additive at concentration of 100 ppm in the fuel. Tests were carried out on chassis dynamometer using continuous repetition of the urban part of the European Driving Cycle as a « worst case » approach. Comparisons are made between the different sizes and positioning as regards both back-pressure build up and catalytic regeneration behavior. The results show that filter regeneration was always possible at continuous low speed driving, at relatively high filter back-pressure levels (i.e. high particulate accumulation in the filter), with an effect on fuel consumption.

The design of a diesel particulate trap system to fit a specific vehicular application requires significant expenditure, due to the high degree of interaction between the vehicle operation and trap behavior. The assistance of modeling in the design process is already well established. This paper presents the basic principles of a Computer Aided Engineering methodology aimed to assist the selection of the basic parameters of a Diesel Particulate Trap System by reducing the number of the necessary experimental tests. The computational modules currently supporting the CAE methodology are based on fundamental mathematical models, incorporating a small number of semi-empirical relations derived by experimental data on trap loading and catalytic regeneration, exhaust system heat transfer and trap backpressure effect on fuel consumption.

A light duty truck Renault Trafic with a naturally aspirated 2.5 l engine was equipped with ceramic DPFs of different sizes, installed at different positions along the exhaust line of the vehicle. The filters were operated on diesel fuel doped with a cerium based additive at concentration of 100 ppm in the fuel. Tests were carried out on chassis dynamometer using the urban part of the new European driving cycle and the full new European Driving cycle. Comparisons are made between the different sizes and positioning as regards both back-pressure build-up and catalytic regeneration behavior. The results show that filter regeneration was always possible at continuous low speed driving, at relatively high filter back-pressure levels (i.e. high particulate accumulation in the filter), with an effect on fuel consumption.

A light duty truck with a naturally aspirated engine was equipped with a DPF (changing the exhaust pipe and eliminating the muffler) and operated on fuel doped with a cerium based additive in various concentrations. Tests were carried out on chassis dynamometer using the European urban cycle, but also under city driving conditions with maximum speeds up to 50 km/h and exhaust gas temperature up to 300°C. Under these conditions, it was observed that filter regeneration was always possible at relatively high particulate accumulation in the filter, while the effect on fuel consumption (as measured over the emission test cycles) was not detectable, compared to baseline data of the vehicle. Change in driving conditions from slow urban to highway with highly loaded trap led to spontaneous trap regeneration at higher temperatures, without effect on fuel consumption. This paper documents the operation of a fully passive DPF system for diesel light duty vehicles.