Mattarelli, E., Rinaldini, C., and Patroncini, P., "Commercial Vehicles: New Diesel Engine Concepts for Euro VI and Beyond," SAE Technical Paper 2017-26-0034, 2017, doi:10.4271/2017-26-0034.
The paper presents a numerical investigation, aimed to explore the potential of 2-stroke Diesel engines, able to meet Euro VI requirements, for application to medium size commercial vehicles (power rate: 80 kW at 2600 rpm, max. torque 420 Nm from 1200 to 1400 rpm). The study is based on experimental performance of a highly developed 4-stroke engine.Two different designs are considered: Loop and Uniflow scavenging, the latter obtained through an opposed piston configuration. In both cases, no poppet valves are used, and the lubrication is provided by a 4-stroke-like oil sump.The study started with the development of a 4-stroke EURO VI engine, on the basis of a previous EURO IV version. A prototype of the new engine (named 430) was built and tested. The second phase of the study consisted in the comparison to the 2-stroke configurations, considering the same performance and emissions targets, as well as the same constraintsEngine outputs are calculated by using GT-Power models: while for the 4-stroke unit these results are fully supported by experimental data, the 2-strokes are just “paper” engines. However, the CFD-1D modeling was supported by other detailed numerical simulations, including both scavenging and combustion analyses.The two stroke concepts analyzed in the paper appear to yield several advantages, in comparison to their 4-stroke counterpart: reduced fuel consumption, cleaner combustion conditions, more compact dimensions, higher flexibility of the EGR control. On the other hand, they require a strong effort for the development of a specific combustion system.